Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada Rev 00, ICN 00

ANL-MGR-GS-000004

February 2005

1. PURPOSE 
This report describes a scientific analysis to bound credible horizontal peak ground velocities 
(PGV) for the repository waste emplacement level at Yucca Mountain. Results are presented as 
a probability distribution for horizontal PGV to represent uncertainties in the analysis. The 
analysis also combines the bound to horizontal PGV with results of ground motion site-response 
modeling (BSC 2004 [DIRS 170027]) to develop a composite hazard curve for horizontal PGV 
at the waste emplacement level. This result provides input to an abstraction of seismic 
consequences (BSC 2004 [DIRS 169183]). The seismic consequence abstraction, in turn, 
defines the input data and computational algorithms for the seismic scenario class of the total 
system performance assessment (TSPA). Planning for the analysis is documented in Technical 
Work Plan TWP-MGR-GS-000001 (BSC 2004 [DIRS 171850]). 
The bound on horizontal PGV at the repository waste emplacement level developed in this 
analysis complements ground motions developed on the basis of PSHA results. In the PSHA, 
ground motion experts characterized the epistemic uncertainty and aleatory variability in their 
ground motion interpretations. To characterize the aleatory variability they used unbounded 
lognormal distributions. As a consequence of these characterizations, as seismic hazard 
calculations are extended to lower and lower annual frequencies of being exceeded, the ground 
motion level increases without bound, eventually reaching levels that are not credible (Corradini 
2003 [DIRS 171191]). To provide credible seismic inputs for TSPA, in accordance with 
10 Code of Federal Regulations (CFR) 63.102(j) [DIRS 156605], this complementary analysis is 
carried out to determine reasonable bounding values of horizontal PGV at the waste 
emplacement level for annual frequencies of exceedance as low as 10-8. For each realization of 
the TSPA seismic scenario, the results of this analysis provide a constraint on the values sampled 
from the horizontal PGV hazard curve for the waste emplacement level. 
The relation of this analysis to other work feeding the seismic consequence abstraction and the 
TSPA is shown on Figure 1-1. The ground motion hazard results from the PSHA provide the 
basis for inputs to a site-response model that determines the effect of site materials on the ground 
motion at a location of interest (e.g., the waste emplacement level). Peak ground velocity values 
determined from the site-response model for the waste emplacement level are then used to 
develop time histories (seismograms) that form input to a model of drift degradation under 
seismic loads potentially producing rockfall. The time histories are also used to carry out 
dynamic seismic structural response calculations of the drip shield and waste package system. 
For the drip shield, damage from seismically induced rockfall also is considered. In the seismic 
consequence abstraction, residual stress results from the structural response calculations are 
interpreted in terms of the percentage of the component (drip shield, waste package) damaged as 
a function of horizontal PGV. The composite hazard curve developed in this analysis, which 
reflects the results of site-response modeling and the bound to credible horizontal PGV at the 
waste emplacement level, also feeds the seismic consequence abstraction. The composite hazard 
curve is incorporated into the TSPA sampling process to bound horizontal PGV and related 
seismic consequences to values that are credible. 
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Figure 1-1. Relations Among Seismic Analysis and Modeling Activities 
In developing time histories to support calculations of the dynamic response of engineered 
barrier system (EBS) components (e.g., drift, drip shield, waste package, pallet), the levels of 
Probabilistic Seismic 
Hazard Analysis 
Ground motion for 
defined reference rock 
outcrop conditions 
Ground Motion Site- 
Response Model 
Ground motion at waste 
emplacement level 
Time History Analysis 
Development of seismograms 
for use in structural analyses 
Drift 
Degradation 
Model 
Evaluation of 
seismic-induced 
rockfall 
Waste 
Package/Cladding 
Seismic Structural 
Calculation 
Evaluation of seismicrelated 
damage to 
waste package and 
cladding 
Drip Shield Seismic 
Structural Calculation 
Evaluation of seismicrelated 
damage (including 
from rockfall) to the drip 
shield 
Horizontal PGV 
Composite 
Hazard Curve 
Analysis 
Probability distribution 
for credible bound to 
horizontal PGV at the 
waste emplacement 
level 
Composite horizontal 
PGV hazard curve for 
the waste 
emplacement level 
Seismic 
Consequence 
Abstraction Model 
Damage abstractions for 
drip shield, waste 
package and fuel 
cladding as a function of 
horizontal PGV 
Total System 
Performance 
Assessment Model 
Seismic scenario class 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
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ground motion determined in the PSHA were used without consideration of their ability to be 
realized at Yucca Mountain. Thus, some of the time histories representing ground motion with 
annual frequencies of exceedance of 10-5, 10-6, and 10-7 (BSC 2004 [DIRS 170027], Section 6.3) 
are unrealistic in that the levels of ground motion calculated likely can not be sustained at Yucca 
Mountain. Nevertheless, they were used to evaluate the performance of EBS components as if 
those levels of ground motion could be achieved to determine the sensitivity of structural 
response calculations to extreme ground motions. The EBS component damage functions based 
on those results, therefore, to some degree represent damage from ground motions that are higher 
than are credible for Yucca Mountain. By incorporating a reasonable bound on horizontal PGV 
at the waste emplacement level into the sampling process for TSPA through the composite 
hazard curve, the sampled horizontal PGV hazard is limited to credible values. 
This analysis depends on predictions of rock deformation that would be caused by extreme 
ground motions at the waste emplacement level at Yucca Mountain and the fact that such 
deformation is not observed. The lack of such deformation is used to conclude that lithophysal 
rocks of the Topopah Spring Tuff have not experienced ground motions large enough to cause 
the predicted deformation during the approximately 12.8 million years (Sawyer et al. 1994 
[DIRS 100075], Table 1) since their deposition. Analysis limitations include the following: 
 The 12.8 million years age of the Topopah Spring Tuff does not preclude the possibility 
that ground motions large enough to cause rock deformation occurred at the Yucca 
Mountain site prior to its deposition or will occur in the future. 
 The lack of observations of the type of rock deformation that would be expected if 
Yucca Mountain had experienced extreme ground motion levels is limited to those 
portions of the mountain that are exposed in the Exploratory Studies Facility (ESF) and 
the Enhanced Characterization of the Repository Block (ECRB) Cross-Drift. Although 
samples and study locations are spatially and stratigraphically distributed throughout the 
rock mass, a small percentage of the total repository rock mass is sampled. 
 Geologic studies of fracture distribution, genesis, and characteristics in the ESF and 
ECRB Cross-Drift were not carried out specifically to look for deformation predicted to 
be associated with extreme ground motion levels. 
 Testing of lithophysal rock samples to provide information on the shear strains 
associated with fracture generation is carried out on laboratory-scale samples. The 
testing of large samples represents an approximation to in situ mechanical behavior. 
 Shear strains at which lithophysal rock of the Topopah Spring Tuff exhibits systematic 
macro-scale fracturing is modeled using a two-dimensional discontinuum numerical 
approach. 
 Modeling to determine the shear strains that would be induced by ground motions in the 
rock at the waste emplacement level employs a one-dimensional equivalent-linear 
approach. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
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 Translation of a probability distribution for the shear strain threshold at which 
geologically observable rock failure would occur due to severe ground motion to an 
equivalent distribution for horizontal peak ground velocity is based on the mean values 
of dynamic shear strain and peak ground velocity from site-response calculations. Mean 
values are used to approximate the translation rather than including the range of results 
due to aleatory variability in site material properties. 
Because of uncertainties in the data, analyses, and modeling, and the limitations listed above, the 
value for a bound on credible horizontal PGV is provided as a probability distribution. 
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2. QUALITY ASSURANCE 
Development of this analysis report and supporting analyses are subject to the Yucca Mountain 
Projects quality assurance program (BSC 2004 [DIRS 171850], Section 8.1). Approved quality 
assurance procedures identified in the technical work plan (BSC 2004 [DIRS 171850], 
Section 4.1), including AP-SIII.9Q (Scientific Analyses), were used to conduct and document the 
activities described in this report. The work was carried out as planned. 
The technical work plan also identifies the methods used to control the electronic management of 
information during the activities (BSC 2004 [DIRS 171850], Section 8.1). Checksums and 
parity checks performed during information transfer and storage, plus existing computer system 
security measures, provide adequate assurance of the integrity of transferred and stored 
information. There were no variances from the planned methods. 
This analysis activity addresses in part characteristics of the bedrock at Yucca Mountain, a 
natural barrier identified on the Q-List as a Safety Category (SC) item per AP-2.22Q 
(Classification Analysis and Maintenance of the Q-List). 
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3. USE OF SOFTWARE 
The section describes software directly used in the analysis. Both qualified software (Table 3-1) 
and commercial-off-the-shelf programs are employed. 
Table 3-1. Qualified Software Used in the Analysis 
Name [DIRS] Tracking Number Version Operating Environment 
LOGNORM [DIRS 170313] 10384-1.01-00 1.01 PC/DOS 6.22-QEMM 9.0 
NORM [DIRS 163313] 10386-1.01-00 1.01 PC/DOS 6.22-QEMM 9.0 
EARTHVISION [DIRS 167994] 10174-5.1-00 5.1 SGI/IRIX 6.5 
The software program LOGNORM V1.01 (Pacific Engineering and Analysis 2004 
[DIRS 170313]) is used to determine the median values of horizontal peak ground velocity and 
shear strain as a function of depth using the results of a suite of previous ground-motion 
site-response model calculations as input. The program was selected for this purpose because it 
has the required capabilities and is part of a suite of programs that were designed and are 
intended to work with and support the ground-motion site-response model calculations. There 
are no limitations on outputs due to the selection of this software. The software was used within 
its range of validation; its ability to determine the average and statistics as a function of depth of 
a parameter with an assumed lognormal distribution has been validated (DOE 2004 
[DIRS 170315], Section 2.3.10). 
The software program NORM V1.01 (Pacific Engineering and Analysis 2002 [DIRS 163313]) is 
used to compute the average horizontal peak ground velocity and shear strain over the average 
depth range for the lower lithophysal zone. The inputs for this computation are median curves as 
a function of depth determined by LOGNORM. The program was selected for this purpose 
because it has the required capabilities and is part of a suite of programs that were designed and 
are intended to work with and support the ground-motion site-response model calculations. 
There are no limitations on outputs due to the selection of this software. The software was used 
within its range of validation; its ability to determine the average and statistics of a parameter has 
been validated (DOE 2002 [DIRS 170314], Section 3.2). 
The software program EARTHVISION V5.1 (Dynamic Graphics 2000 [DIRS 167994]) is used 
to determine the average depth range for the lower lithophysal unit of the Topopah Spring Tuff. 
Input to the program consists of the Geologic Framework Model (Data Tracking Number (DTN) 
MO0012MWDGFM02.002 [DIRS 153777]). The program was selected for this purpose 
because it is the program used to develop the geologic model of the Yucca Mountain site. There 
are no limitations on outputs due to the selection of this software. The software was used within 
its range of validation. 
Commercial-off-the-shelf software programs Microsoft Excel 97 SR-2 and Microsoft 
Excel 2000 were used in carrying out several components of the analysis. Standard functions of 
the programs were used and results are not dependent on use of these particular spreadsheet 
programs. Formulae used, input data, and output values are documented in Appendix D to this 
report. 
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Microsoft Excel was used in evaluation of geologic data to sort fracture data and to determine 
the percentages of fractures with certain characteristics. The program also was used to display 
the results of the evaluations. Appendix D contains the workbooks (PGV ECRB DLS 
Frac-Fill.xls, PGV SSF DLS Frac-Fill.xls) developed for analysis of fracture data showing the 
input data and results. Formulae used also are included. 
Microsoft Excel was also used to identify the intact shapes of lithophysae versus structural 
damage that might result from post-cooling stresses induced by seismic shaking. Appendix D 
contains the workbook (PGV Lithop Shapes ECRB.xls) used to compile and analyze descriptions 
and photographic interpretations of lithophysal cavity data in the ECRB Cross-Drift. 
Information on inputs, outputs, and formulae are contained in the workbook. 
Microsoft Excel also was used in determining the shear strain increment that lithophysal rock 
underwent in being deformed from in situ conditions to failure. Similar spreadsheets were 
developed for analysis of both laboratory test results and results of numerical simulations. 
Inputs, outputs, and formulae used are documented in Appendix D (Limiting strains -Lab 
Tests.xls, Limiting strains -Numerical Sims.xls). 
Microsoft Excel also was used to average the horizontal peak ground velocity and shear strain 
values determined for two wave propagator types (vertical and inclined propagation). For each 
annual frequency of exceedance considered, the average values are computed for the 
8 combinations of base-case velocity profile, base-case dynamic property curves, and oscillator 
frequency range. These combinations reflect uncertainties in the input parameters and also the 
range of earthquakes that contribute to the annual frequency that a given level of ground motion 
will be exceeded. Inputs, outputs, and formulae used are documented in Appendix D 
(PGV&Strain-Average of Vertical & Inclined Results.xls). 
Microsoft Excel also was used to determine values of horizontal peak ground velocity at 
specified values of dynamic shear strain. For each of the 8 cases representing uncertainty in site 
properties, linear interpolation or extrapolation was used based on the results in the workbook 
PGV&Strain-Average of Vertical & Inclined Results.xls. Inputs, outputs, and formulae used are 
documented in Appendix D (PGV v Shear Strain.xls). 
Microsoft Excel also was used to compute probability densities and seismic hazard curves for 
the waste emplacement level. Probability densities were computed for shear strain threshold 
using a triangular distribution. Probability densities for horizontal PGV were determined from 
the triangular distribution for shear strain threshold. An unbounded horizontal PGV hazard 
curve for the emplacement level was determined from results of site-response modeling. 
Modified hazard curves for horizontal PGV at the emplacement level are determined from the 
hazard curve for unbounded motions and the probability distributions for the bound on horizontal 
peak ground velocity. Inputs, outputs, and formulae used are documented in Appendix D 
(Probability Distributions.xls). 
Commercial-off-the-shelf software programs CorelDraw 9 and CorelDraw 10 were also used in 
the analysis. These programs were used to display data as part of the evaluation of geologic data 
from mapped panels in the ECRB Cross-Drift. 
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Two other software programs also are mentioned in this report, but are not used in the analysis. 
PFC2D (Software Tracking Number [STN] 10828-2.0-01) (BSC 2004 [DIRS 169930]) and 
UDEC (STN 10173-3.1-00) (BSC 2002 [DIRS 161949]) were used in previous modeling and 
analysis activities to simulate compressive tests of Topopah Spring Tuff (BSC 2003 
[DIRS 166660], Attachments V, VI, VIII). In this analysis, the results of the previous work are 
used and the software programs cited to indicate which program was used to generate which 
result. Because the software programs are not used in this analysis, they are not included in 
Table 3-1. 
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4. INPUTS 
This section describes the direct inputs, criteria, and codes for the analysis. 
4.1 DIRECT INPUTS 
Direct inputs are used in carrying out five components of the analysis: 
1. Evaluation of geologic data from the ESF and the ECRB Cross-Drift for evidence of 
ground motion-induced damage to the rock. 
2. Interpretation of laboratory rock testing data to determine the shear-strain threshold at 
which failure occurs for lithophysal rock. 
3. Evaluation of previous numerical simulations of lithophysal rock deformation to 
determine the shear-strain threshold at which failure occurs. 
4. Evaluation of previous ground-motion site-response model results to determine the 
level of shear strain that is associated with various levels of horizontal PGV at the 
waste emplacement level. 
5. Development of a hazard curve for horizontal PGV at the waste emplacement level. 
This section lists the direct inputs used (Table 4-1) and discusses their appropriateness. 
Table 4-1. Direct Inputs Used in the Analysis 
Description Data Tracking Number 
Detailed Line Survey Data For Stations 00+00.89 to 14+95.18, 
ECRB Cross-Drift 
GS990408314224.001 [DIRS 108396] 
Detailed Line Survey Data For Stations 15+00.85 to 26+63.85, 
ECRB Cross-Drift 
GS990408314224.002 [DIRS 105625] 
Detailed Line Survey Data for Horizontal and Vertical Traverses, 
ECRB 
GS040108314224.001 [DIRS 169591] 
Lithophysal Study Data from the Tptpll in the ECRB from stations 
14+44 to 23+26 [especially see the part on Panel Maps] 
GS021008314224.002 [DIRS 161910] 
ESF, ECRB Cross-Drift Small Scale Fracture Study: Detailed Line 
Survey Data for Horizontal and Vertical Traverses 2003 
GS040408314224.003 [DIRS 170312] 
Fractures in slabs of core in crystallized Topopah Spring Tuff GS040808314224.005 [DIRS 171964] 
Mechanical Properties Of Lithophysal Tuff, Batch #1 (Test Dates: 
July 31, 2002 Through August 16, 2002) 
SN0208L0207502.001 [DIRS 161871] 
Mechanical Properties Of Lithophysal Tuff, Batch #2 (Test Dates: 
October 22, 2002 Through October 25, 2002) 
SN0211L0207502.002 [DIRS 161872] 
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Table 4-1. Direct Inputs Used in the Analysis (Continued) 
Description Data Tracking Number 
BSC (Bechtel SAIC Company) 2003. Subsurface Geotechnical 
Parameters Report. 800-K0C-WIS0-00400-000-00A. Las Vegas, 
Nevada: Bechtel SAIC Company. ACC: ENG.20040108.0001. 
[DIRS 166660] 
Not applicable 
BSC (Bechtel SAIC Company) 2004. Development of Earthquake 
Ground Motion Input for Preclosure Seismic Design and 
Postclosure Performance Assessment of a Geologic Repository at 
Yucca Mountain, NV. MDL-MGR-GS-000003 REV 01. 
Las Vegas, Nevada: Bechtel SAIC Company. [DIRS 170027] 
MO0409MWDGMMIO.000 [DIRS 172216] 
Geologic Framework Model (GFM2000) MO0012MWDGFM02.002 [DIRS 153777] 
Peak Ground Velocity for the Repository Level (Point B) at 10-4 
Annual Exceedance Frequency 
MO0404PGVRL104.000 [DIRS 170437] 
Peak Ground Velocity for the Repository Level (Point B) at 10-5 
Annual Exceedance Frequency 
MO0401SEPPGVRL.022 [DIRS 169099] 
Peak Ground Velocity for the Repository Level (Point B) at 10-6 
Annual Exceedance Frequency 
MO0303DPGVB106.002 [DIRS 162712] 
Peak Ground Velocity for the Repository Level (Point B) at 10-7 
Annual Exceedance Frequency 
MO0210PGVPB107.000 [DIRS 162713] 
Geologic mapping data on the occurrence and genesis of fractures within lithophysal units of the 
Topopah Spring Tuff (DTNs: GS990408314224.001 [DIRS 108396], GS990408314224.002 
[DIRS 105625], GS040108314224.001 [DIRS 169591], GS040408314224.003 [DIRS 170312], 
and GS040808314224.005 [DIRS 171964]) are used in Section 6.3 to evaluate whether observed 
joints and faults exhibit characteristics expected for features created by extreme levels of ground 
motion. Fracture data associated with these DTNs are considered in making this evaluation. 
Representative panel maps (Table 4-2, DTN GS021008314224.002 [DIRS 161910]) were also 
examined to compare observed features with those predicted by numerical modeling of rock 
failure. 
Table 4-2. Panel Map Images Examined in this Analysis 
Image Identification Image Identification Image Identification Image Identification 
PP0660L PP0816R PP1035L SSF1886L 
PP0660R PP0910L PP1035R SSF1920L 
PP0740L PP0910R PP1220L SSF2019L 
PP0740R PP0935L PP1218R SSF2071L 
PP0815L PP0935R SSF1805L SSF2125L 
Source: Appendix A, Table A4-1 
These geologic data are appropriate for use in this analysis because they represent the available 
geologic information on the characteristics of fractures in the lithophysal units of the Topopah 
Spring Tuff and the spatial relation of those fractures to lithophysae. While the data were not 
specifically gathered for the purpose of comparison to numerical modeling results of rock 
damage, the data are adequate to determine whether the observed features are indicative of the 
type of pervasive deformation that is predicted if extreme levels of ground motion were to have 
occurred. 
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Results of laboratory testing to determine the mechanical properties of lithophysal rock 
(DTNs: SN0208L0207502.001 [DIRS 161871] and SN0211L0207502.002 [DIRS 161872]) are 
used in Section 6.4.1 to determine the shear strain increment in deforming the rock from in situ 
conditions to failure. Specific data used are values for Youngs modulus, Poissons ratio, and 
ultimate strength. Data from all samples were used. Data on the length-to-diameter ratio of 
tested samples are used to identify a subset of samples with a ratio greater than 1.5. In addition 
to determining statistics for the shear strain increment based on all samples, statistics for this 
subset also are computed. 
These particular mechanical property data are appropriate for use because they were determined 
from tests of 288-mm-diameter samples of lithophysal rock from the Topopah Spring Tuff. 
Mechanical properties determined from such large-diameter samples better reflect the behavior 
of the in situ rock in that they can include larger lithophysae than smaller samples. Data for 
lithophysal rock are analyzed because the lithophysal rock units are weaker than the 
nonlithophysal units. They would, therefore, show evidence of ground motion-related damage at 
lower levels of ground motion than would nonlithophysal rock. 
Data on the lithophysal content of rock samples tested is used in displaying the shear strain 
threshold results, but is not used directly in the analysis. The lithophysal content data are 
included in the data set with DTN: SN0305L0207502.005 [DIRS 163373]. 
To complement the results of laboratory testing, numerical simulations of the mechanical 
behavior of lithophysal rock from the Topopah Spring Tuff (BSC 2003 [DIRS 166660], 
Attachments V, VI, VIII) also are used in Section 6.4.2 to determine the shear strain increment in 
deforming the rock from in situ conditions to failure. In these numerical simulations, which 
were carried out previously, lithophysae were represented in alternative ways. For simulations 
using the software code PFC2D (STN 10828-2.0-01) (BSC 2004 [169930]), lithophysae were 
represented both as 90 mm circles and using shape stencils based on observations in the ECRB. 
For simulations using the software code UDEC (STN 10173-3.1-00) (BSC 2002 
[DIRS 161949]), lithophysae were represented as 90 mm circles. Results of all three sets of 
simulations are used in this analysis. 
Specific data used from each simulation are Youngs modulus, Poissons ratio, yield stress, and 
peak stress. For the simulations that used the software code PFC2D, Youngs modulus, 
Poissons ratio, and peak stress are taken from the file ShapeStudy.xls (BSC 2003 
[DIRS 166660], Attachment VIII, Compact Disc 1:\AppD_CD01\PFC_runs\ShapeStudy\). For 
the simulations that used the software code UDEC, Youngs modulus, Poissons ratio, friction 
angle, and peak stress are taken from the file summary2_newest.xls (BSC 2003 [DIRS 166660], 
Attachment VIII, Compact Disc 20:\UDEC_CD1\). Values of yield stress are determined for 
both PFC2D and UDEC simulations by plotting volumetric strain and axial stress as a function 
of axial strain from restored *.SAV files (BSC 2003 [DIRS 166660], Attachment VIII, Compact 
Discs 2 through 24). As for the laboratory testing results, data on the lithophysal porosity 
(BSC 2003 [DIRS 166660], Attachment VIII, ShapeStudy.xls, summary2_newest.xls files) of 
each simulated sample tested is used in displaying the shear strain threshold results, but is not 
used directly in the analysis. 
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The numerical simulations of the mechanical behavior of Topopah Spring Tuff lithophysal rock 
are the result of previous modeling activity (BSC 2003 [DIRS 166660], Sections 9.1, 9.2 and 
Attachments V, VI, and VIII]; BSC 2004 [DIRS 166107], Sections 7.5 and 7.6; BSC 2004 
[DIRS 172334], Section 6.5). They are appropriate inputs because they model the strains 
developed in such rock as the rock is stressed to failure. Numerical simulations, conducted with 
a suitably-calibrated model, complement the results from laboratory testing by allowing 
representation of synthetic rock samples that contain more variable lithophysae shapes, 
distributions, and levels of porosity than can be physically tested. The simulations also allow a 
large number of numerical testing simulations to be run in which full control of applied pressures 
and monitoring of deformation response is possible. It is therefore possible to fully explore the 
variability of lithophysal rock mass strain at failure for the range of expected in situ conditions. 
Ground-motion site-response modeling data (DTN: MO0409MWDGMMIO.000 
[DIRS 172216]) are used in Section 6.5 to determine the level of horizontal PGV associated with 
various levels of ground-motion-induced shear strain. Lack of geologic evidence of rock damage 
predicted to result from extreme levels of ground motion is used to conclude that shear strain 
levels that would cause such damage have not occurred and, hence, the associated levels of 
horizontal PGV also have not occurred at Yucca Mountain. Specific data used from the 
ground-motion site-response modeling results are the variation of horizontal PGV and shear 
strain with depth from the surface to the bottom of the modeled site materials. Results for 
ground motion with annual frequencies of exceedance of 10-4, 10-5, 10-6, and 10-7 are used to 
cover the range of uncertainty in the level of shear strain at which damage would occur. For 
each annual frequency of exceedance, the input to the analysis consists of results from a suite of 
2880 model runs to accommodate variability and uncertainty in site dynamic material properties 
and the range of earthquake magnitudes and distances contributing to the seismic hazard. 
These ground-motion site-response data are the result of previous modeling (BSC 2004 
[DIRS 170027], Section 6.3.4). They are appropriate for use in this analysis because they 
provide the link between ground-motion-induced strain and horizontal PGV at the waste 
emplacement level. Because the ground motion input to the site-response modeling is based on 
the results of the PSHA for Yucca Mountain, the results incorporate the uncertainties and 
randomness that were determined as part of the PSHA process. Because uncertainties and 
randomness in site dynamic material properties are also accommodated in the site-response 
modeling, the resulting horizontal PGV and shear strain data are consistent with the hazard level 
of the input ground motions. 
Ground motion site-response modeling data for horizontal PGV at the waste emplacement level 
(DTNs: MO0404PGVRL104.000 [DIRS 170437], MO0401SEPPGVRL.022 [DIRS 169099], 
MO0303DPGVB106.002 [DIRS 162712], and MO0210PGVPB107.000 [DIRS 162713]) are 
used to develop a hazard curve. They are appropriate for this use because they represent the 
site-specific horizontal PGVs for the waste emplacement level with annual frequencies of 
exceedance of 10-4, 10-5, 10-6, and 10-7, respectively. The horizontal PGV hazard curve 
developed from these data represents unbounded ground motions. A composite hazard curve 
that incorporates the effect of a bound to horizontal PGV at the waste emplacement level also is 
developed. 
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4.2 CRITERIA 
Project requirements are identified in Project Requirements Document (TER-MGR-MD-000001) 
(Canori and Leitner 2003 [DIRS 166275]). The requirements that pertain to this analysis report 
and their links to 10 CFR 63 [DIRS 156605] are summarized in Table 4-3. 
Table 4-3. Project Requirements Pertaining to the Bounding Peak Ground Velocity Analysis 
Requirement Number Title 10 CFR 63 Link 
PRD-002/T-004 Content of Application 10 CFR 63.21 
PRD-002/T-011 Purpose and Nature of Findings 10 CFR 63.101 
PRD-002/T-015 Requirements for Performance Assessment 10 CFR 63.114 
This report addresses criterion PRD 002/T-004 by describing a reasonable bound to horizontal 
PGV that potentially affect the performance of the geologic repository at Yucca Mountain. It 
thus provides information needed for a complete description of the site. 
This report addresses criterion PRD 002/T-011 by describing the technical basis and justification 
for the range of parameter distributions characterizing a reasonable bound to horizontal PGV at 
Yucca Mountain. This distribution is used in assessing the performance of a repository. 
This report addresses criterion PRD 002/T-015 by describing horizontal PGV that form part of 
the information on disruptive events that is used to evaluate the performance of a repository at 
Yucca Mountain. The report also describes the uncertainties and variability in parameter values 
that provide input to the analysis of a credible bound to horizontal PGV and the alternative 
models considered. 
Criteria are also provided by the Yucca Mountain Review Plan, Final Report (NRC 2003 
[DIRS 163274]). Relevant acceptance criteria from this document are: 
 Acceptance criteria listed in Section 1.5.3 of NRC (2003 [DIRS 163274]) are based on 
meeting requirements of 10 CFR 63.21(b)(5) [DIRS 156605], which relate to description 
of site characterization work: 
1. The General Information section of the license application contains an adequate 
description of site characterization activities. 
2. The General Information section of the license application contains an adequate 
description of site characterization results. 
This report addresses Part 1 of criterion 1 and Parts 1 and 2 of criterion 2 by providing a 
reasonable bound to horizontal PGV that forms part of the description of site 
characterization activities and results. 
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 Acceptance criteria listed in Section 2.2.1.2.2.3 of NRC (2003 [DIRS 163274]) are 
based on meeting requirements of 10 CFR 63.114(d) [DIRS 156605], which relate to 
identification of events with probabilities greater than 10-8 per year: 
1. Events are adequately defined. 
2. Probability estimates for future events are supported by appropriate technical 
bases. 
3. Probability model support is adequate. 
4. Probability model parameters have been adequately established 
5. Uncertainty in event probability is adequately evaluated. 
This report addresses Parts 1 and 2 of criterion 1, Part 1 of criterion 2, Part 1 of criterion 
3, Part 1 of criterion 4, and Part 1 of criterion 5 by describing the technical justification 
for a reasonable bound to horizontal PGV that is used to analyze performance of the 
repository. The bound is based on models of rock deformation and ground motion and on 
empirical observations from laboratory testing and geologic investigations. In addition, 
the report discusses how inputs to the analysis were determined and how uncertainties are 
accommodated by the analysis. 
 Acceptance criteria in Section 2.2.1.3.2.3 of NRC (2003 [DIRS 163274]) are based on 
meeting the requirements of 10 CFR 63.114(a) (c) (e) and (g) [DIRS 156605], which 
relate to mechanical disruption of engineered barriers: 
2. Data are sufficient for model justification. 
3. Data uncertainty is characterized and propagated through the model abstraction. 
This report addresses Parts 1 and 3 of criterion 2 and Parts 1, 2, and 3 of criterion 3 by 
describing the use of data to develop inputs to the seismic consequence abstraction model 
and how data uncertainty is incorporated into the analysis. 
The Yucca Mountain Review Plan, Final Report (NRC 2003 [DIRS 163274]) also provides 
information on the review methods that will be used to assess whether the acceptance criteria 
have been met. Review methods specifically relevant to the analysis described in this report are: 
Section 2.2.1.2.2.2 
Review Method 1 Event Definition 
Evaluate whether the definitions for events (potentially beneficial or disruptive), 
applicable to the Yucca Mountain repository, are unambiguous; probabilities are 
estimated for the specific event; and event definitions are used consistently and 
appropriately in probability models. 
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Confirm that probabilities of intrusive and extrusive igneous events are calculated 
separately. Verify that definitions of faulting and earthquakes are derived from 
the historical record, paleoseismic studies, or geological analyses. Confirm that 
criticality events, for the purpose of initial screening of the features, events, and 
processes list, are calculated separately, only by location of the criticality event 
(e.g., in package, near field, and far field). 
Review Method 2 Probability Estimates 
. . . Verify that probability estimates for future faulting and seismic events have 
considered past patterns of these events in the Yucca Mountain region. Examine 
the adequacy and sufficiency of characterization and documentation of past 
faulting and seismicity in the Yucca Mountain region, since 2 million years ago. 
This should include characterization of uncertainties in the age, timing, magnitude 
(i.e., displacements), distribution, size, location, and style of faulting and 
seismicity. Evaluate whether interpretations of faulting and seismicity from 
surficial and underground mapping, interpretations of geophysical data, or analog 
investigations are internally consistent and geologically feasible, so reasonable 
projections can be made about the probability of future faulting and earthquake 
induced ground vibrations at the site. 
Review Method 4 Probability Model Parameters 
Verify whether the parameters used to calculate the probability of events, 
applicable to the Yucca Mountain repository, are reasonable, based on data from 
the Yucca Mountain region or analogous natural systems, and/or design and 
engineering characteristics of the proposed Yucca Mountain repository system. 
. . . Verify whether parameter values used in probabilistic seismic and fault 
displacement hazard assessments are adequately supported by Yucca Mountain 
region faulting and earthquake data or appropriate analogs, so the effects of 
faulting and seismicity are appropriately factored into repository performance. 
Verify that parameters are consistent with the range of faulting characteristics and 
seismicity observed in the Yucca Mountain region, or with parameters derived 
from representative analogs, and ascertain that the parameters account for 
variability in data precision and accuracy. For example, confirm that the 
U.S. Department of Energy adequately evaluated uncertainties in faulting or 
earthquake activity (i.e., recurrence). Confirm that the U.S. Department of 
Energy has established reasonable and consistent correlations between 
parameters, where appropriate. Where sufficient data do not exist, confirm that 
parameter values and conceptual models are based on appropriate use of other 
sources, such as expert elicitation, using NUREG1563 (Kotra et al., 1996). 
Review Method 5 Uncertainty in Event Probability 
. . . Verify that probabilities used in the evaluation of faulting and seismicity 
effects on repository performance include both infrequent seismic and faulting 
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events with relatively large magnitude ground motions and fault displacements, 
and the cumulative effects of repeated ground motions or fault displacements 
from more frequent and lower magnitude seismic or faulting events. 
4.3 CODES, STANDARDS, AND REGULATIONS 
There are no codes or standards other than those discussed in Section 4.2 that pertain to the 
analysis of a reasonable bound to horizontal PGV. 
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5. ASSUMPTIONS 
Assumptions are used, in the absence of direct confirming data or evidence, in the analysis of 
results of lithophysal rock deformation, both from laboratory testing and from numerical 
simulation. These assumptions are described below. 
1. For laboratory testing of lithophysal rock samples, if Poissons ratio is not determined, a 
value of 0.3 is assumed in calculating the shear-strain increment from in situ conditions 
to failure. About 80 percent of Poisson ratio determinations for lithophysal rock at Yucca 
Mountain fall in the range of 0.1 to 0.3 (BSC 2003 [DIRS 166660], Figure 8-58). The 
mean value is 0.21. A value of 0.3 is assumed in the shear-strain increment calculations 
(if a value from testing is unavailable) because larger values of Poissons ratio result in 
larger calculated shear-strain increments. Larger shear-strain increments lead to a larger 
shear-strain threshold, which implies a higher bound to horizontal PGV. The assumption 
is used in Section 6.4. 
2. For both laboratory testing and numerical simulation of the deformation of lithophysal 
rock samples, if the friction angle is not determined, a value of 30 degrees is assumed in 
calculating the shear-strain increment in going from in situ conditions to failure. Values 
of internal friction angle for intact lithophysal rock at Yucca Mountain, determined from 
compressive test results, vary from about 45 to 60 degrees (BSC 2003 [DIRS 166660], 
Table 8-40). Numerical simulation results for the lithophysal rock mass indicate internal 
friction angles ranging from about 30 to 40 degrees (Appendix D, Limiting 
Strain-Numerical Sims.xls, Worksheet UDEC 250m). A value of 30 degrees is 
assumed for internal friction angle (if test results or numerical simulation results do not 
include a value) because smaller values of internal friction angle result in larger 
calculated shear-strain increments. Larger shear-strain increments lead to a larger 
shear-strain threshold, which implies a higher bound to horizontal PGV. The assumption 
is used in Section 6.4. 
3. In determining the in situ stress state for the lithophysal rocks of the Topopah Spring 
Tuff, a lithostatic stress gradient of 0.01925 MPa/m depth is assumed. This value is used 
in calculating the magnitude of the vertical stress (s1) for two representative depths 
(250 and 400 m) for the repository emplacement level. This value is consistent with the 
unit weight calculated from information provided in the Drift Degradation Analysis 
(BSC 2004 [DIRS 166107], Table E-1) for units of the Paintbrush Group. Determination 
of the shear-strain increment in going from in situ conditions to failure is insensitive to 
reasonable values of unit weight. The assumption is used in Section 6.4. 
4. In determining the in situ stress state for the lithophysal rocks of the Topopah Spring 
Tuff, it is assumed that the magnitude of the horizontal stress is 0.5 times that of the 
vertical stress. This is consistent with results from a hydraulic fracturing investigation in 
the ESF (CRWMS M&O 1997 [DIRS 147458], pp. 1, 15, 16) that determined a 
horizontal to vertical stress ratio of 0.3 to 0.7, taking into account the range of horizontal 
stress and uncertainties in the results. If the upper value from the range were assumed, 
calculated shear strain increments (percent strain) would be higher by a few to about 
10 percent. The assumption is used in Section 6.4. 
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6. SCIENTIFIC ANALYSIS DISCUSSION 
6.1 INTRODUCTION 
The purpose of this analysis report is to establish a reasonable bounding peak ground velocity 
(PGV) for the emplacement level of the Yucca Mountain site (Point B of BSC (2004 [170027], 
Figure 1-1)). This site-specific PGV is assessed to be appropriate considering annual frequencies 
of exceedance as low as 10-8/yr. PGV is the ground motion measure that is correlated with 
potential seismic damage to the engineered barrier system (EBS) components in the seismic 
consequence abstraction (BSC 2004 [DIRS 169183], Section 6.1.3). The results of the PSHA are 
expressed as seismic hazard curves at a hypothetical rock outcrop (Point A of (BSC 2004 
[DIRS 170027], Section 6.2.2)). Site response analyses are used to modify the Point A ground 
motions to account for site-specific material properties (BSC 2004 [DIRS 170027]) and to 
develop seismic hazard curves that are appropriate for conditions at the emplacement level of the 
repository (Point B). The annual frequency of exceedance of ground motions and the amplitudes 
of the ground motions, expressed as PGV, are used as input to the seismic consequence 
abstraction (BSC 2004 [DIRS 169183]). In turn, the results of the consequence abstraction are 
input to the seismic scenario that is used in the TSPA (Figure 1-1). 
Analysis of the response of EBS components to various levels of ground motion has shown that 
damage occurs at PGV amplitudes that are associated with annual frequencies less than or equal 
to 10-6/yr (BSC 2004 [DIRS 169183], Sections 6.1.3 and 6.3). At these annual frequencies down 
to 10-8/yr, the mean hazard estimate is quite sensitive to the tails of the ground motion 
attenuation distribution, which is represented by unbounded lognormal distributions on the 
aleatory variability. As a result, the mean hazard curve lies well above the median hazard curve 
and above the 85th percentile curve (BSC 2004 [DIRS 170027] Figures 6.2-1 through 6.2-3). In 
addition, the assessed epistemic (scientific) uncertainty in ground motion attenuation is large for 
the large-magnitude, short-distance earthquakes that control the seismic hazard at annual 
frequencies of exceedance in the range 10-6 to 10-8. It is judged that the resulting mean PGV 
values at these annual frequencies of exceedance may be physically unrealistic (Reiter 2004 
[DIRS 170694]). The present analysis is aimed at estimating a bounding horizontal PGV that 
has a physical basis. This bound, which is represented as a probability distribution to account for 
uncertainties, is then used to limit the level of mean PGV values at annual frequency levels down 
to 10-8/yr. 
6.2 APPROACH 
The approach taken to assess bounding PGV for the emplacement level of the Yucca Mountain 
site is to consider physical limits on the amplitude of ground motions. Amplitudes of ground 
motions are limited by the strength of the materials through which they propagate. At high 
enough levels of seismic shaking the rocks at the emplacement level, particularly the lithophysal 
tuffs, would undergo mechanical damage, would fracture, and fail. A key geologic finding in the 
ESF and ECRB is the absence of mechanical damage of the type expected from extreme seismic 
shaking in the 12.8-million-year old volcanic rocks at the emplacement level. There are fractures 
and minor faults observed in the excavations, but these appear to be related primarily to the early 
cooling history of the rocks or, in the case of known faults, localized zones of displacement. 
Extreme seismic shaking over dimensions of the repository would result in widespread damage. 
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The absence of such damage means that the rocks have not experienced ground motions of 
sufficient amplitude to cause failure since the time that they were deposited. Laboratory tests 
and modeling provide the means of assessing the shear strain increments required to cause failure 
of the lithophysal rock. In turn, ground motion modeling provides a means of assessing the 
site-specific ground motions that would cause these shear strains. Through this approach, the 
amplitudes of ground motions are assessed that have not been achieved or exceeded during the 
past 12.8 million years at the emplacement level of Yucca Mountain. This conclusion provides 
the basis for the analysis of reasonable bounds on PGV. 
Rock testing data, geologic data, and ground-motion site response data are combined to 
determine a bound to horizontal PGV. The analysis consists of four steps. First, laboratory 
testing and numerical simulations of lithophysal rock deformation are used to determine the 
shear-strain threshold for rock failure. Second, the results of the numerical simulations are 
combined with geologic observations in the ESF and ECRB Cross-Drift to conclude that the 
Topopah Spring lithophysal zones have not experienced shear-strains exceeding the threshold for 
failure. Third, ground-motion site response data are used to assess the level of horizontal PGV 
that would be required to generate shear strains exceeding the shear-strain threshold for failure. 
Fourth, it is concluded that such a level of horizontal PGV has not been reached at Yucca 
Mountain since the rocks were deposited 12.8 million years ago. This is taken as a reasonable 
bound for the level of ground motion to be considered in TSPA. 
Key issues associated with the approach are the following: the resolution of the geologic 
observations, including identifying the origins of fractures and features and their association with 
depositional (e.g., cooling of the tuffs) or post-depositional processes (e.g., seismic shaking); 
threshold shear strain levels associated with failure of the lithophysal tuffs, given in situ stress 
conditions; definition of failure criteria that are consistent with the resolution of the geologic 
observations; and PGV ground motions associated with particular levels of threshold shear 
strain. Each of these key issues is associated with uncertainty and the approaches to addressing 
these uncertainties are given in Sections 6.3, 6.4, and 6.5. 
The analysis of maximum ground motions conducted for the PEGASOS project in Switzerland 
(Abrahamson et al. 2004 [DIRS 170686]) consisted of evaluating limits based on considerations 
of seismic source properties, as well as limitations in the strength capacities of the soils 
underlying the sites. The approach being followed for the present analysis is analogous to the 
latter approach used in Switzerland inasmuch as limits on the shear strength of the local 
transmission medium provide a fundamental constraint on the amplitude of the ground motions. 
The analysis presented in this report uses the results of testing and modeling of the shear strains 
required to fail the lithophysal rocks at the emplacement level, and the results of the geologic 
evidence for the lack of seismically-induced damage, to arrive at a probability distribution on 
failure or threshold shear strain. Threshold shear strain values are then translated into ground 
motions (PGV) using the site response model for Yucca Mountain at the emplacement level. 
The resulting PGV values are then combined with the failure shear strain probability distribution 
to arrive at a probability distribution on bounding PGV. 
The concept used to develop a bounding ground motion distribution is analogous to defining a 
maximum earthquake magnitude that defines the upper bound to an earthquake recurrence 
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relationship for probabilistic seismic hazard analyses (Budnitz et al. 1997 [DIRS 103635], 
Section 4.2.2). Maximum magnitudes are specific to individual seismic sources. Because the 
historical record is usually short relative to the recurrence interval for the largest earthquake that 
a seismic source can generate, the assessment of maximum magnitude is uncertain and 
commonly expressed as a probability distribution (Budnitz et al. 1997 [DIRS 103635], 
Section 4.3.2). There is no single unique method of estimating maximum magnitude. Typically, 
the assessment is made considering a combination of observed seismicity data and physical 
constraints. The observed record includes earthquakes that have occurred in association with the 
particular seismic source historically, as well as earthquakes that have occurred in association 
with analogous seismic sources. Physical constraints include estimates of the maximum 
dimensions of rupture that a seismic source might entail (e.g., fault rupture length, displacement 
per event). These various data and estimates, none of which individually provides a unique 
maximum magnitude estimate, are used to develop a judgment expressed as a probability 
distribution on maximum magnitude for a seismic source of interest (Budnitz et al. 1997 
[DIRS 103635], Section 4.3.2), reflecting the epistemic uncertainty. 
In a comparable way, the bounding ground motion is rare and uncertain, it is specific to the site 
of interest, and there is no single dataset that uniquely defines it. Approaches to estimating 
bounding ground motions include consideration of the observational record, including both 
site-specific and analogue ground motion recordings, as well as physical constraints on seismic 
source properties, transmission path, and local strength characteristics. The approach taken in 
this analysis focuses on ground motion limits based on strength properties of the rock. The result 
of the analysis is a probability distribution on bounding PGV that, much like a maximum 
magnitude distribution, reflects the epistemic uncertainty. 
Subsequent sections of this report provide the documentation for the steps outlined in this 
approach. Section 6.3 summarizes the geologic observations regarding the presence or absence 
of seismic shaking-related damage in the lithophysal tuffs comprising the emplacement level of 
the repository. Section 6.4 summarizes the testing and modeling information related to the tuffs 
and the threshold shear strain distribution that is developed in light of that information. 
Section 6.5 provides a summary of the site-specific ground motion calculations that translate the 
threshold shear strain values into PGV values at the emplacement level. Section 6.6 presents the 
bounding PGV distribution, which is assessed through a consideration of the geologic data, 
testing and modeling, and ground motion calculations. 
6.3 GEOLOGIC OBSERVATIONS REGARDING SEISMICALLY-INDUCED 
DAMAGE 
A key element of the approach to bound horizontal PGV at the waste emplacement level is using 
the geologic data collected in the ESF and ECRB Cross-Drift to determine whether pervasive 
seismically-induced fracturing and other rock damage has occurred at Yucca Mountain. The 
features in a rock represent the major processes that have occurred throughout its geologic 
history; therefore, the features are used to reconstruct the sequential development of the 
rock-forming processes. This sequential development of features is placed in a temporal (or 
petrogenetic) framework that constrains how and when subsequent processes occurred. 
Furthermore, this petrogenetic framework is used to evaluate whether the rocks have ever 
experienced shear strains great enough to result in mechanical failure. One of the prime sources 
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of shear strain to be considered is that associated with paleoseismic events. Three types of 
geologic observations were made to evaluate whether pervasive seismically-induced fracturing 
has occurred at Yucca Mountain in the rocks of the repository horizon since their deposition: 
(1) evaluation of the petrogenesis of fractures relative to their association with deposition/cooling 
versus mechanical damage subsequent to cooling; (2) evaluation of damage or collapse of 
lithophysal cavities in response to shear strains; and (3) comparison of rock mechanics modeling 
of inter-lithophysal fractures with panel photographs in the ECRB. A summary discussion of 
these geologic observations is given in Sections 6.3.1 through 6.3.4 and a detailed discussion is 
provided in Appendix A. 
6.3.1 Petrogenesis of Fractures 
The lithostratigraphic units in the Topopah Spring Tuff comprising the repository host horizon 
consist of densely welded, crystallized, and lithophysal or nonlithophysal rocks. Fractures in the 
densely welded and crystallized ignimbrites of the Topopah Spring and Tiva Canyon Tuff are 
identified on the basis of crystallization and mineralization features as cooling fractures, which 
includes Type 1 and Type 2 fractures (Buesch et al. 1999 [DIRS 165483]) and post-cooling 
fractures, herein referred to as Type 3 fractures. During the welding process, the redistribution 
of the vapor phase resulted in development of lithophysae and transfer of the vapor phase along 
fractures. During and shortly after the development of lithophysal cavities and early-formed 
(Type 1) fractures, the glass crystallized in the presence of the vapor along the margins of 
lithophysal cavities and fractures to form light gray to pinkish gray rims. Even some of the 
matrix-groundmass surrounding the lithophysae and some fractures crystallized to form grayish 
red purple borders and reddish gray matrix-groundmass, and these features are consistent with 
crystallization of the matrix-groundmass in the presence of vapor. Fractures that formed late in 
the cooling history of the deposit do not have rims, formed when the rock was mostly (if not 
entirely) crystallized, and these fractures are indicative of Type 2 fractures. Vapor-phase mineral 
coatings typically are on cooling fractures, but they are not necessarily on all cooling fractures 
because the fracture could have formed after most of the vapor phase had been removed from the 
area, or the three-dimensional network of fractures simply did not penetrate a region of abundant 
vapor phase material. Lack of distinctive features such as rims or vapor-phase mineral coatings 
means that some Type 2 fractures might not be identified as being cooling fractures and might be 
identified as Type 3 fractures (those that formed after the rock had cooled to the ambient 
temperatures of a rock at the paleogeomorphic surface). Therefore, some of the indeterminate 
fractures (those that do not have distinctive cooling related features such as rims or 
vapor-phase mineral coatings) can be consistent with being Type 2 cooling fractures. 
Samples for mapping of fractures on slabs of core were collected from two surface-based 
boreholes and 32 tunnel-based boreholes located in the ESF Main-Drift and the ECRB 
Cross-Drift. These boreholes were used to collect samples that represent different 
lithostratigraphic zones, spatial variations within the zones, samples from different sizes of core, 
and samples to be compared to those collected near the tunnel walls to evaluate induced fractures 
from the tunnel boring machine. Detailed Line Survey (DLS) data on fractures in the ECRB 
were also evaluated as part of this assessment. Although the DLS data focused on geometric 
relations of the fractures, other features such as rims developed on fracture walls and material 
coating or filling the fractures also were documented. 
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Of the 2,022 fractures mapped in the densely welded and crystallized rocks of the Topopah 
Spring Tuff, 69.7 percent (1,410 fractures) are cooling related fractures and 30.3 percent 
(612 fractures) are indeterminate, although these indeterminate fractures might also have formed 
during the late stage of cooling (see discussion in Section A1.1). These relations are also 
represented by the cooling to indeterminate ratio (C/I ratio) for each sample where the total 
number of cooling fractures are divided by the total number of indeterminate fractures 
(Figure 6-1). A C/I ratio of 1 indicates there are equal numbers of cooling and indeterminate 
fractures in a sample; a ratio larger than 1 indicates there are proportionately more cooling 
fractures than indeterminate fractures; and a ratio smaller than 1 indicates there are 
proportionately less cooling fractures than indeterminate fractures. The C/I ratio is plotted by 
sample (Figure 6-1a) or as a distribution function for each lithostratigraphic unit (Figure 6-1b). 
For lithostratigraphic units with greater than 5 samples, there is an asymmetric distribution of the 
C/I ratios with cooling fractures being more abundant than indeterminate fractures. This 
indicates the strong influence of stresses induced during cooling on the formation of fractures. 
To calculate the C/I ratio and avoid division into or by 0, if there are no cooling or 
indeterminate fractures in a sample, then a value of 0.1 is assigned to that type of fracture in that 
sample. 
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Source: DTN GS040808314224.005 [DIRS 171964]. 
NOTES: Table A1-2 in Appendix A provides an explanation of the symbols for the various lithostratigraphic units. 
For the shortened versions used on the x-axis in part a), the leading Tpt is dropped. 
a) C/I ratios of individual samples plotted by lithostratigraphic zone or subzone. 
b) The number of C/I ratio values in 5 x 10x increments plotted by lithostratigraphic zone or subzone. 
Lines are only plotted for units with 5 or more samples. 
Figure 6-1. Cooling to Indeterminate Ratio (C/I ratio) of Fractures by Lithostratigraphic Zone or 
Subzone in the Densely Welded and Crystallized Topopah Spring Tuff 
Data from the fractures in slabs of core and DLS in the ECRB Cross-Drift were collected for 
different reasons and represent different scales of sample size and resolution; however, they lead 
to a consistent set of conclusions regarding the petrogenesis of fractures: (1) approximately 
70 percent of fractures are positively related to cooling and 30 percent are indeterminate (but 
might be late-stage cooling related), and (2) the vast majority of fractures have no evidence of 
shear or mechanical degradation. 
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6.3.2 Lithophysal Cavities 
Lithophysal cavities developed very early in the formation of the rock and may be indicators of 
applied strains. Of the 1410 lithophysae described in the panel maps and inventoried in the panel 
photographs, all the lithophysae have shapes that are consistent with the initial formation of the 
lithophysae during welding of the ignimbrite. An example of the panel maps is given in 
Figure 6-2. 
Source: Panel maps in DTN GS021008314224.002 [DIRS 161910]. 
NOTE: Panel map at station location 21+25 on the left rib with photograph and mapped features displayed 
separately. Lithophysal cavities are labeled in red with red lines outlining the cavity and green lines 
outlining the rim. Spots are labeled in cyan with outlines in cyan. Lithic clasts are labeled in orange and 
outlined in orange. 
Figure 6-2. Example Panel Map of Lithophysal Cavities, Lithophysal Rims, Spots, and Lithic Clasts 
None of the lithophysae show damage or collapse that could be the result of extreme 
earthquake ground motions. Of the 1,444 lithophysae inspected, only 7 are transected (or 
intersected) by fractures greater than 1 m in trace length (the fractures were mapped during 
collection of DLS data), and only 5 are transected by shears. Although a few lithophysae are 
transected by fractures, are the terminal end of fractures, or occur along shears, none have 
appreciable effects of damage to the walls of the lithophysae. 
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6.3.3 Inter-lithophysal Fractures 
On the basis of numerical simulations of rock mechanic properties using the software code 
PFC2D (BSC 2003 [DIRS 166660], Attachments V, VIII), one of the most diagnostic relations 
of lithophysal rocks that have been subjected to shear strains greater than about 0.1 to 0.2% is the 
development of a pervasive network of inter-lithophysal fractures (Section 6.4 and Appendix B). 
Twenty photographs of tunnel walls in rocks that contain lithophysae from the upper lithophysal 
and lower lithophysal zones (including two photographs from the lithophysae-bearing subzone of 
the middle nonlithophysal zone), were examined to evaluate the geometry of fractures and their 
relation to lithophysae. Most of the relations of lithophysae and fractures in the photographs are 
consistent with (1) localized in situ fracturing of the matrix-groundmass during cooling of the 
rock mass, or (2) minor amounts of extension of the rock mass, probably during structural tilting 
of the mountain. A pervasive network of inter-lithophysal fractures is not observed. An 
example of the interpretations made of the panel maps is given in Figure 6-3. 

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Source: GS021008314224.002 [DIRS 161910] and BSC (2003 [DIRS 166660], Attachment V-Appendix B, Figure B-4). 
NOTE: Upper part of figure shows stress-strain model results (BSC 2004 [DIRS 172334]) using the software code PFC2D. Blue lines are micro-fractures 
formed prior to failure at peak strength and red lines are micro-fractures formed post-failure at peak strength. Embedded lithophysae are derived from 
stencils taken from the panel map below. The lower part of the figure is the panel map at 16+24 on the right wall with 300 photographically interpreted 
fractures (yellow lines). 
Figure 6-3. Comparison of Modeled Fracture Development in Lithophysal Rock Samples that are Deformed to Failure to Observed Fractures in 
the Enhanced Characterization of the Repository Block Cross-Drift 

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6.3.4 Conclusions from Geologic Observations 
Data from the systematic characterization of fractures in boreholes and detailed examination of 
panel maps and photographs in the ECRB Cross-Drift supports a cooling-related origin for most 
fractures observed in underground exposures of lithophysal rock of the Topopah Spring Tuff. 
Collapsed lithophysae and widespread fractures with characteristics (shear offset, 
inter-lithophysal connections) that would be expected if the shear strain threshold for lithophysal 
rock had been exceeded at Yucca Mountain are not seen. Although the samples used in the 
studies are limited in size and scale relative to the entire rock mass, one of the underlying 
strengths of these studies is that samples and study locations are spatially and stratigraphically 
distributed throughout the rock mass. Thus it is concluded that the shear-strain threshold for 
failure of lithophysal rock at Yucca Mountain has not been exceeded since the rocks were 
deposited about 12.8 million year ago. 
6.4 THRESHOLD SHEAR STRAIN DISTRIBUTION FOR TOPOPAH SPRING 
LITHOPHYSAL ROCK 
This section summarizes previously performed laboratory testing and modeling results that are 
used to relate shear strain increments to rock damage, and uses that information to develop a 
probability distribution on a threshold shear strain that would lead to geologically observable 
damage in Topopah Spring Tuff lithophysal rock. The geologic evidence for the absence of such 
damage has been summarized in Section 6.3 and described in Appendix A. A more detailed 
description of the numerical determination of the relationship of strain to damage for lithophysal 
rock is given in Appendix B. 
Both laboratory testing and numerical modeling have been used to study the mechanical 
behavior of lithophysal rock at Yucca Mountain. Laboratory testing provides mechanical 
properties data, including strength and strain at initial yield and at peak stress, from the upper 
and lower lithophysal units of the Topopah Spring Tuff at Yucca Mountain 
(DTNs: SN0208L0207502.001 [DIRS 161871] and SN0211L0207502.002 [DIRS 161872]). 
For the analysis summarized here (and discussed in more detail in Appendix B), large samples 
(288-mm diameter) are used. The larger sample size contains numerous lithophysae and thus the 
mechanical properties derived from this testing are more representative of in situ conditions in 
the repository host horizon. 
Numerical models using the software codes PFC2D and UDEC (BSC 2003 [DIRS 166660], 
Attachments V, VI, VIII) complement the laboratory testing results. These models have been 
calibrated to reproduce the observed mechanical response and failure mechanisms of lithophysal 
rock. These calibrated numerical models therefore provide a mechanical simulation tool that is 
used: 1) to understand the basic mechanics of deformation and failure mechanisms of 
lithophysal rocks, and 2) as a means to extend the laboratory testing results to understand the 
impact of in situ variability of the sizes, shapes and distribution of lithophysal cavities on the 
range of mechanical response (e.g., stress-strain behavior) and failure mechanisms. Using the 
calibrated models, it is also possible to examine the expected observable physical condition of 
the rock mass as a function of the applied stress and shear strain history. The observable 
physical conditions may include the mode and extent of lithophysae deformation and intact rock 
matrix fracturing that would be expected if the rock mass were subjected to specific 
seismically-induced stress and shear strain histories. 
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Figure 6-4 illustrates typical fracturing predicted by the calibrated PFC2D model occurring in a 
simulated (synthetic) lithophysal rock sample that has been stressed to failure under uniaxial 
compression. In this simplest of modeling approaches, the lithophysal voids are represented as 
circular holes distributed throughout the sample. The rock matrix in this model is composed of 
several thousand circular particles (too small to be seen at this scale) which are bonded with 
tensile and shear bonds at their contacts. Fractures, which occur due to breakage of these contact 
bonds when the sample is stressed, can be seen as red and blue lines within the sample. Analyses 
of compression of synthetic rock samples show that stress-induced fractures would be expected 
to interconnect the lithophysae, which act as locations of stress concentration within the mass. 
This form of predicted fracture development  ubiquitous, long inter-lithophysal 
fracturing  would allow such fractures to be distinguished in underground observations from the 
typical cooling fractures as described in Appendix A. 
The modeling has been used to simulate shear strain states in the synthetic lithophysal rock 
samples that would be expected in situ if the rock mass were subjected to seismic events. The 
threshold shear strain is the shear strain at which the lithophysal rock would undergo damage1 
that would be recognizable to geologists in the field. Correlation of this damage state directly to 
shear strain is uncertain because development of damage is a progressive process that evolves 
with increased levels of strain. Clearly, the state at which the first microfractures appear in the 
intact rock matrix would be an underestimate of the threshold shear strain, because a few 
unconnected fractures would be unnoticed in the field. A more appropriate threshold shear strain 
level can be derived by taking into account the stress-strain response for typical brittle rocks. 
When a brittle rock is loaded in compression, it is typical to monitor the applied stress difference 
(the axial stress minus the confining stress) as well as the axial and lateral (or circumferential) 
strains. The stress-strain response of the sample is typically plotted as the axial stress versus 
axial strain (see Appendix B, Figures B-3 and B-6) as well as the volumetric (axial plus 
circumferential) strain versus the axial strain (see Appendix B, Figure B-3). The typical 
stress-strain plot shows an initial nonlinear portion related to seating of the loading platens and 
closure of open microfractures related to drilling and removal of the sample from its in situ stress 
condition. This is followed by a linear portion of the plot related to loading of the sample and 
defines the elastic modulus of the material. The stress-strain curve then departs from linearity, 
indicating the beginning of microfracture development. Coalescence of the microfractures into 
through-going macrofractures results in macroscopic failure of the sample and defines its peak 
strength. 
It is straightforward in the calibrated numerical model to define the shear strain levels at which 
micro fracturing and peak strength are reached, and to display the physical deformation and 
fracturing state that would be observed at each of these strain levels. In particular, the strain at 
which yield is reached is most easily defined as the point at which the volumetric strain begins to 
reverse, indicating dilation of the lateral strains (see Appendix B, Figure B-3). The reversal of 
the volumetric strain (dilation) occurs as a result of rapid coalescence of microfractures into 
macrofractures, and represents a lower bound to the peak strength. The strain state at the peak 
1 Damage here refers to the physical effects of permanent deformation of the rock mass that develop in response to 
applied strain. The damage may take the form of new fractures, deformed or collapsed lithophysae, new shear 
deformation and/or dilation of existing cooling fractures, etc. 
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stress is an upper bound to the threshold strain representing the state for which the fractures 
connecting lithophysae are pervasive and would be distinguishable in the geologic panel maps of 
the ESF and the ECRB Cross-Drift. Appendix B also discusses an intermediate state at which 
the onset of systematic fracturing (OSF) is attained. While the physical damage state associated 
with these various strain states are documented based on the results of the numerical simulations, 
data from the laboratory tests provide information only on the peak stress (strength) of the 
samples. Thus, for this analysis the assessment of shear-strain threshold is carried out on the 
basis of peak stress. This approach results in higher shear-strain increments and a higher bound 
to horizontal PGV than if one of the other damage states, based on lower shear-strain increments, 
were used. 
Source: Damjanac et al. (2004 [DIRS 172060], Figure 1). 
NOTE: Blue and red lines indicate stress-induced fractures developed during a simulated uniaxial compression test. 
The arrows indicate the direction of applied uniaxial compression. Blue lines indicate fractures that 
developed prior to reaching the peak stress; red lines indicate fractures that developed after the peak stress 
was reached. Fractures located in the middle of a circular void represent particles that have broken off 
from the edge of the void. The modeling was carried out using the software code PFC2D (BSC 2004 
[DIRS 169930]). 
Figure 6-4. Fractures Developed during Modeled Deformation of a 1-Meter by 1-Meter Synthetic 
Lithophysal Sample 
The laboratory tests and numerical simulations on which the assessment of threshold shear strain, 
and the associated uncertainty, are based are discussed below in Sections 6.4.1 and 6.4.2. 
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ANL-MGR-GS-000004 REV 00 6-13 February 2005 
6.4.1 Laboratory Test Results 
Uniaxial compression tests were conducted on samples from lithophysal and nonlithophysal 
Topopah Spring Tuff (Price 2004 [DIRS 170894]). Testing of lithophysal tuff is particularly 
challenging due to the lithophysae. Large diameter samples are required for determination of 
representative rock mass mechanical properties. As expected, the mechanical properties of the 
lithophysal tuff exhibit a strong dependence on porosity, which, in turn, can be viewed as a form 
of sample size dependency. Therefore, the results obtained from the tests on the largest samples, 
the 288-mm diameter cores (diameter several times larger than the included lithophysae) taken 
from the ESF and ECRB Cross-Drift, are considered to be the best representation of the 
mechanical behavior of the lithophysal tuff. The uniaxial compression tests provide stress-strain 
behavior of the lithophysal tuff, which includes the axial stress and strain levels associated with 
peak strength. 
The axial strain to failure measured in uniaxial compression tests cannot be used directly as the 
strain increment required to cause fracturing of lithophysal rock because this strain corresponds 
to a particular uniaxial stress (and corresponding strain) path from the initial, unstressed state to 
the failure state. The rock mass exposed in the Yucca Mountain ESF and ECRB Cross-Drift is 
already under an in situ state of stress (and strain) with a significant deviatoric component. The 
horizontal principal stress components are between 30% and 70% of the vertical principal stress 
(CRWMS M&O 1997 [DIRS 147458], pp. 1, 15, 16) (see Assumption 4 in Section 5). In 
Appendix B, a methodology is discussed for calculating the shear-strain increment that 
corresponds to the stress change from the in situ stress state to the limiting stress state defined by 
the yield condition for the rock (see Appendix B, Figure B-4). It is assumed that the lithophysal 
rock mass behaves as a linear elastic material until the limiting state is reached. The stress path 
from the initial stress state to the limiting state during a strong seismic ground motion can be 
arbitrary. In this analysis, the shear strain increment is calculated for the stress path in which the 
mean stress does not change. Cyclic shear strain under constant vertical stress, which is typically 
a dominant mode of deformation during a seismic ground motion, results in the stress path along 
which the mean stress is invariant. 
The shear strain increments at peak strength were calculated for laboratory results obtained on 
19 288-mm diameter samples taken from the ESF and ECRB Cross-Drift. The experimental 
results were obtained for unconfined compression conditions only. An internal angle of friction 
of 30 was assumed in the calculation (Section 5, Assumption 2). This assumption results in 
conservative (larger) estimates of the shear strain associated with peak strength and thus larger 
potential peak ground velocities to produce observable yield in situ. The results for the 288-mm 
diameter samples, using an overburden depth of 250 m and divided into two categories based on 
height-to-diameter ratio ( / 1.5 H D> and / 1.5 H D= ), are shown in Figure 6-5 as a function of 
lithophysal porosity. It is preferred to have the height-to-width, or height-to-diameter, ratio for 
the laboratory test sample equal to or larger than 2 to minimize the effect of friction between the 
loading plates and the sample. The sample to platen friction exerts a small radial confining stress 
to short-length samples, thus resulting in artificially higher compressive strengths. Note that the 
results show no relationship between shear strain at failure and lithophysal porosity (Figure 6-5). 
Statistics of the results are presented in Table 6-1. 
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Table 6-1. Summary of Statistics of Calculated Shear Strain Limits Based on 250 m of Overburden 
Number of 
Samples Mean 
Standard 
Deviation 
% % 
288-mm diameter, H/D > 1.5 13 0.16 0.04 
288-mm diameter, all 19 0.18 0.07 
Source: Appendix B, Table B-2 
0.00% 
0.10% 
0.20% 
0.30% 
0.40%
0% 10% 20% 30% 40% 
Porosity 
Shear Strain 
H:D > 1.5 
H:D = 1.5 
Source: Appendix B, Figure B-7. 
NOTE: Shear-strain increments are calculated for an overburden depth of 250 m. For this case, the mean 
shear-strain increment for all 288-mm diameter samples is 0.18% strain. For the samples having a ratio 
/ 1.5 H D> , which are considered the best representation of the mechanical behavior of lithophysal rock, the 
mean shear-strain increment is 0.16% (Table 6-1). The bold horizontal dashed lines indicate the lower and 
upper bound of the shear strain threshold probability distribution developed in Section 6.4.3. 
Figure 6-5. Calculated Shear Strain Increment for 288-mm Diameter Samples 
6.4.2 Numerical Simulation Results 
To supply additional evidence regarding threshold shear strain levels, the results of the existing 
numerical tests, which were conducted to examine the effect of lithophysal porosity on the 
mechanical properties of tuff, are re-analyzed to determine the strain at particular damage states 
(see Appendix B for detailed discussion). The simulations were carried out using PFC2D 
(BSC 2004 [DIRS 169930]) and UDEC (BSC 2002 [DIRS 161949]). PFC2D represents the rock 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 6-15 February 2005 
as a bonded assembly of disks whereas UDEC represents the rock as a bonded assembly of 
polygons. The results of the numerical simulations are reported by BSC (2004 [DIRS 172334], 
Section 6.5) and incorporated into BSC (2003 [DIRS 166660], Sections 9.1, 9.2, Attachments V, 
VI, and VIII). The original reports provide details of the various numerical models and testing 
procedures. 
The numerical models of the rock mass first were calibrated to reproduce the mechanical 
behavior observed in the laboratory compression tests (BSC 2004 [DIRS 172334], Section 6.5). 
Subsequently, the effects of changing lithophysal porosity and shape of lithophysae were 
investigated. Thus, it is assumed in the numerical analysis that lithophysal porosity and 
lithophysae shape are the only parameters affecting mechanical behavior of the lithophysal rock 
mass. The distribution of the lithophysae within a laboratory sample can also impact the 
strength, resulting in additional variability in test results. This is probably the main reason the 
numerical results show less scatter than what is observed in the laboratory tests. The numerical 
models, however, clearly show the controlling impact of lithophysal voids on strength and elastic 
modulus, and demonstrate the same trends in strength and modulus with porosity as observed in 
the laboratory. 
Results of the numerical compressive tests show that the lithophysal rock will fail through the 
development of fractures that extend generally from one lithophysal void to another (Figure 6-4) 
(BSC 2004 [DIRS 172334], Section 6.5). The failure mechanism is a function of tensile splitting 
between adjacent lithophysal voids that is caused by the induced tensile stresses in the material 
between the voids. Strains induced by extreme ground motion would be expected to cause this 
style of deformation (i.e., fractures that connect lithophysae). Thus, seismic-induced fracturing 
would be distinguishable from fractures related to cooling of the deposits, which do not typically 
show intersections with lithophysae (Appendix A). 
Shear-strain increments required to deform the numerical synthetic samples from in situ 
conditions to failure were determined. Shear strain increments were calculated for two failure 
criteria: peak stress (strain state at ultimate strength) and yield stress (state at volumetric strain 
reversal). Values of Youngs modulus, Poissons ratio, friction angle, peak stress, and yield 
stress were taken from the results of the numerical simulations. If a friction angle was not 
determined as part of the numerical simulation, a value of 30 degrees was used (Section 5, 
Assumption 2). Shear-strain increments were calculated for in situ conditions at two 
representative waste emplacement level depths: 250 and 400 m. 
The shear strain increments are calculated and, as an example, Figure 6-6 shows the results for 
the state at peak stress at 250 m overburden. The results for three types of 2D simulation are 
superimposed on the graph shown in Figure 6-6: (a) circular voids, modeled by PFC2D; 
(b) actual complex shapes traced from geologic field maps (stenciled voids), modeled by 
PFC2D; and (c) circular voids, modeled by UDEC. In Figure 6-6, the engineering shear strain 
(axial strain minus lateral strain) increment for a peak stress state is plotted against lithophysal 
porosity. Mean shear strain increments and standard deviations are listed in Table 6-2. 
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ANL-MGR-GS-000004 REV 00 6-16 February 2005 
Source: Appendix B, Figure B-9. 
NOTE: Shear strain increment determined for an overburden depth of 250 m. Numerical simulations carried out 
using software codes PFC2D and UDEC. The bold horizontal dashed lines indicate the lower and upper 
bound of the shear strain threshold probability distribution developed in Section 6.4.3. 
Figure 6-6. Shear Strain Increment Determined Using the Peak-Stress Criterion, Overburden = 250 m 
0.00% 
0.05% 
0.10% 
0.15% 
0.20% 
0.25% 
0.30% 
0.35%
0% 10% 20% 30% 
Lithophysal Porosity 
Shear Strain Increment 
PFC2D+Circles 
PFC2D+Actual 
UDEC+Circles 
Peak Stress 
250 m Overburden
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Table 6-2. Mean Shear-strain Increments Determined from Numerical Simulation of the Mechanical 
Behavior of Lithophysal Rock 
Failure Criterion = Peak Stress Failure Criterion = Yield Stress Depth for In Situ 
Conditions 
(m) 
Simulation 
Approach 
Shear Strain Incrementc (%) 
(mean  standard deviation) 
Shear Strain Increment (%) 
(mean  standard deviation) 
PFC2D+Circlesa 0.15  0.02 0.14  0.02 
PFC2D+Actualb 0.13  0.03 0.11  0.04 
250 
UDEC+Circles 0.11  0.02 0.09  0.03 
PFC2D+Circles 0.16  0.02 0.15  0.02 
PFC2D+Actual 0.15  0.03 0.12  0.05 
400 
UDEC+Circles 0.12  0.02 0.10  0.03 
a Lithophysae are represented in model as circular holes. 
b Lithophysae are represented in model as actual complex shapes traced from geologic field maps. 
c Shear strain increment is the increment in shear strain from the in situ stress state to the failure criterion. Failure 
criterion based on either a peak failure stress or yield stress condition. 
Source: Appendix D, Limiting Strains-Numerical Sims.xls 
Although the UDEC and PFC2D models were calibrated to the same laboratory results, the shear 
strain increment calculated from the UDEC results is systematically smaller than the shear strain 
increment calculated from the PFC2D results. One reason for this is that the UDEC synthetic 
sample is calibrated in such a way that its strength is slightly less than the strength of the PFC2D 
sample; at the same time, stiffness of the UDEC sample is larger than the stiffness of the PFC2D 
sample, resulting in the smaller strain increment calculated based on UDEC results. The other 
reason is that shear strain increment based on the PFC2D results is calculated assuming a friction 
angle of 30 (Section 5, Assumption 2). The shear strain increment based on the UDEC results is 
calculated using friction angles determined from the UDEC results, which generally are larger 
than 30. In this case, smaller friction angles result in larger shear strain increments. 
6.4.3 Assessment of Threshold Shear Strain Probability Distribution 
Given the laboratory test data and the numerical simulations discussed in Sections 6.4.1 
and 6.4.2, an assessment is made of the shear strain level at which geologically-observable 
damage would occur. This level is termed the threshold shear strain level for this analysis. As 
discussed previously in Section 6.4, the damage state associated with the peak stress is selected 
as the damage state for this analysis. Modeling studies described in Appendix B examined the 
evolution of axial stress, volumetric strain and the onset of systematic fracturing as functions of 
axial strain. The differences between strains at peak stress, at the point of volumetric strain 
reversal, and at the onset of systematic fracturing are relatively small (See Appendix B, 
Section B2.1, Figure B-3). These results justify use of shear strain increments determined for the 
state at peak stress as a reasonable threshold shear strain. 
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ANL-MGR-GS-000004 REV 00 6-18 February 2005 
0.00 
2.00 
4.00 
6.00 
8.00 
10.00 
12.00 
14.00
0.00 0.05 0.10 0.15 0.20 0.25 0.30 
Shear-Strain Threshold (% strain) 
Probability Density 
Source: Appendix D, Probability Distributions.xls. 
Figure 6-7. Assessed Probability Distribution of Threshold Shear Strain for Topopah Spring Lithophysal 
Rock 
Epistemic uncertainty in the assessment of the threshold shear strain is represented by the 
triangular probability distribution in Figure 6-7. The mode of the distribution is 0.16% strain, 
which is the mean of the testing data for the 288-mm-diameter samples with ratio / 1.5 H D> 
(Table 6-1). This value also is consistent with the mean estimates based on the PFC2D 
numerical simulations, which range from about 0.13% to 0.18% (Table 6-2). The lower limit of 
the triangular distribution lies at 0.09% strain, which bounds the shear strain increments for the 
288-mm diameter laboratory test data (Figure 6-5). The upper limit of the distribution lies at 
0.25%, which bounds most of the shear strain limits from the laboratory tests (Figure 6-5). As 
shown in Figure 6-5, two of the laboratory determinations of shear strain increment (for samples 
with H/D less than or equal to 1.5) fall outside the assessed distribution. This is justified because 
the focus of the assessment is on the shear-strain threshold for the weaker rock at Yucca 
Mountain, which would show pervasive inter-lithophysal fracturing at lower ground motions. 
The laboratory results for samples with H/D less than or equal to 1.5 would likely overestimate 
the shear strain threshold. The numerical simulations suggest the upper value of shear-strain 
threshold is closer to 0.20%. Calculation of the probability density for the triangular distribution 
is documented in Microsoft Excel workbook Probability Distributions.xls on worksheet 
Shear-Strain Threshold (Appendix D). 
6.5 GROUND MOTION CALCULATION 
This section summarizes the analysis of ground motions for the threshold shear strain 
distribution assessed in Section 6.4.3. The analysis is given in Appendix C and results in the 
horizontal peak ground velocity (PGV) associated with threshold shear strains for the repository 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 6-19 February 2005 
horizon. Ground motion site-response modeling has been carried out for the Yucca Mountain 
site (BSC 2004 [DIRS 170027], Section 6.3). As part of the site response output, information is 
provided on the variation with depth (from the surface to the waste emplacement level) of the 
peak ground velocity and dynamic strain. By comparing the calculated horizontal PGV and 
dynamic shear strain at the depth of the Topopah Spring Tuff lower lithophysal unit for a suite of 
ground motion levels, the shear-strain threshold determined from laboratory testing and 
numerical simulations is associated with a value of horizontal PGV. That is, the results of the 
site response modeling are used to determine the level of horizontal PGV that would be required 
to generate dynamic shear strains in the lithophysal rock that exceed the threshold at which the 
rock would fail producing geologically observable damage. 
As part of the process to develop seismic inputs for postclosure analyses, the ground-motion 
site-response model is run for various combinations of input parameters. These combinations 
reflect uncertainties in the input parameters and also the range of earthquakes that contribute to 
the annual frequency that a given level of ground motion will be exceeded. Ground motions 
forming input to the site-response model (i.e., control motions) are developed for two frequency 
ranges (5 to 10 Hz and 1 to 2 Hz) to account for the fact that, at a given hazard level, different 
earthquakes dominate the ground motion at different frequency ranges of the response spectrum. 
Relatively close earthquakes usually dominate at higher frequencies, while larger, but more 
distant earthquakes can dominate at lower frequencies. Also, because the dynamic behavior of 
the site materials is potentially nonlinear, the range of earthquake magnitudes contributing to the 
hazard for each frequency range is also important. Three earthquakes represent the range of 
magnitudes for each of the two frequency ranges, resulting in six earthquakes for each 
component of ground motion (the deaggregation earthquakes) that form the control motion for 
the site-response model. Finally, both vertically propagating seismic waves and inclined seismic 
waves are considered in the modeling process. 
Uncertainty and variability in the dynamic properties of the site materials also is accommodated 
in the site-response model. Uncertainty is incorporated through use of alternate base-case 
velocity profiles and alternate base-case sets of dynamic material property curves. Variability is 
incorporated by stochastically varying the velocity profiles and dynamic material property curves 
about their base case. 
The uncertainty and variability in the base-case properties translates into uncertainty in the level 
of horizontal PGV that is associated with a particular shear-strain threshold. For each 
combination of base-case velocity profile (P1 or P2), base-case dynamic property curves (Upper 
Mean Tuff [UMT] or Lower Mean Tuff [LMT]), and wave propagator type (inclined or 
vertically incident), site response is determined using the deaggregation earthquakes as the input 
control motion. For a given combination, each deaggregation earthquake control motion is 
propagated through 60 randomized velocity profiles with associated randomized dynamic 
property curves producing 60 curves of horizontal PGV and shear strain versus depth. Results 
for the three deaggregation earthquakes associated with each frequency range (5 to 10 Hz and 1 
to 2 Hz) are combined and then median PGV and median dynamic shear strain values versus 
depth are determined. To characterize the median PGV and dynamic shear strain for the 
lithophysal units, PGV and strain are averaged for the depth range from 290 to 392 m (951 to 
1,286 ft), the average depth range of the lower lithophysal unit of the Topopah Spring Tuff 
(Appendix C, Section C2.2). For each combination, the values obtained for the two types of 
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wave propagators (vertical and inclined) are then averaged resulting in eight pairs of PGV and 
shear strain corresponding to the combinations examined (1 to 2 Hz/P1/UMT, 
1 to 2 Hz/P1/LMT, 1 to 2 Hz/P2/UMT, 1 to 2 Hz/P2/LMT, 5 to 10 Hz/P1/UMT, 
5 to 10 Hz/P1/LMT, 5 to 10 Hz/P2/UMT, 5 to 10 Hz/P2/LMT). This process is carried out for 
4 hazard levels (10-4/yr, 10-5/yr, 10-6/yr, 10-7/yr) resulting in a suite of values associating 
horizontal PGV and dynamic shear strain (Table 6-3). In addition to the 8 pairs of shear strain 
and corresponding horizontal PGV values determined for the 4 hazard levels, those results were 
also used to linearly interpolate or extrapolate horizontal PGV values for target values of shear 
strain (0.05, 0.10, 0.20, 0.30, 0.40, 0.50%) (Table 6-3). These results are used in Section 6.6 to 
determine a reasonable bound for horizontal PGV at the waste emplacement level for Yucca 
Mountain. 

ANL-MGR-GS-000004 REV 00 6-21 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Table 6-3. Modeled and Interpolated/Extrapolated Horizontal Peak Ground Velocity for Shear Strain Values 
Annual 
Frequency of 
Exceedance 
(1/yr) 
Velocity Profile P1 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P1 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P2 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P2 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled Shear 
Strain (.yz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(.yz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(.yz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(.yz, %) 
1  10-4 45.26 0.020 47.27 0.023 45.17 0.018 43.67 0.024 
1  10-5 110.67 0.050 104.48 0.076 111.40 0.048 105.82 0.089 
1  10-5 242.65 0.118 231.98 0.263 244.31 0.116 231.41 0.331 
1  10-7 512.01 0.270 499.27 0.869 519.61 0.272 494.90 1.041 
Velocity Profile P1 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P1 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P2 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P2 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled Shear 
Strain (.yz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(.yz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(.yz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(.yz, %) 
1  10-4 31.63 0.016 29.65 0.018 31.33 0.016 30.00 0.021 
1  10-5 99.29 0.051 93.24 0.072 99.70 0.049 93.86 0.085 
1  10-5 246.20 0.124 237.70 0.276 249.51 0.127 235.68 0.351 
1  10-7 520.46 0.286 522.41 0.905 540.36 0.297 518.23 1.089 
Source: Appendix D, PGV v Shear Strain.xls 
ANL-MGR-GS-000004 REV 00 6-22 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Table 6-3. Modeled and Scaled Horizontal Peak Ground Velocity for Shear Strain Values (Continued) 
Velocity Profile P1 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P1 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P2 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P2 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Target Shear 
Strain Values 
(.yz, %) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
0.05 110.67 76.09 115.92 68.38 
0.10 208.44 120.67 213.93 111.34 
0.20 388.85 188.96 392.95 163.43 
0.30 566.06 248.31 568.86 215.52 
0.40 743.27 292.46 744.78 257.18 
0.50 920.48 336.60 920.69 294.27 
Velocity Profile P1 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P1 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P2 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P2 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Target Shear 
Strain Values 
(.yz, %) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
0.05 97.74 67.48 100.73 58.98 
0.10 198.04 113.13 197.97 101.63 
0.20 375.26 183.91 374.89 155.04 
0.30 545.08 248.56 545.47 208.44 
0.40 714.90 293.83 716.06 254.44 
0.50 884.72 339.09 886.64 292.73 
Source: Appendix D, PGV v Shear Strain.xls 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 6-23 February 2005 
6.6 BOUND TO HORIZONTAL PEAK GROUND VELOCITY EXPERIENCED AT 
YUCCA MOUNTAIN 
Results in Sections 6.3, 6.4, and 6.5 are combined in this section to determine a bound to the 
level of horizontal peak ground velocity experienced at the waste emplacement level. 
Laboratory tests and numerical simulations of lithophysal rock deformation demonstrate the 
shear-strain increments that would be required to fracture such rock at Yucca Mountain. These 
results are used to establish a shear-strain threshold for fracturing. The numerical simulation 
results also show the characteristics of fractures that would develop. These fractures would tend 
to develop such that they connect lithophysae. Geologic observations indicate that the rock 
exposed in the ESF and ECRB Cross-Drift does not exhibit this type of fracturing; the 
shear-strain threshold for fracturing has not been exceeded. Thus, it is inferred that ground 
motions that would generate dynamic shear strains exceeding the threshold have not occurred at 
the waste emplacement level during the past 12.8 million years (the age of the Topopah Spring 
Tuff). Site-response modeling determines the level of horizontal PGV that would be associated 
with dynamic shear strains that exceed the shear-strain threshold and cause fracturing. This 
allows a bound to be established for the level of horizontal PGV that has been experienced at the 
waste emplacement level at Yucca Mountain. This bound is then taken to be a reasonable bound 
for the level of horizontal PGV that is considered in TSPA. 
Given the uncertainties in the available data, the bounding horizontal PGV is expressed as a 
probability distribution. The triangular distribution for shear-strain threshold discussed in 
Section 6.4.3 is used to develop distributions for bounding horizontal PGV. To translate the 
shear-strain threshold probability distribution into a distribution for horizontal PGV at the waste 
emplacement level, the results of the ground-motion site-response modeling are used. For each 
of the eight site-response modeling cases, which represent epistemic uncertainty in the velocity 
profile and dynamic material properties at Yucca Mountain (and the two frequency ranges), the 
values of shear strain and corresponding horizontal PGV are used to transpose the shear-strain 
threshold distribution (Figure 6-7) to one for horizontal PGV. This results in 8 probability 
distributions for horizontal PGV (Figure 6-8) (Appendix D, Probability Distributions.xls). The 
resulting distributions for horizontal PGV depart slightly from a triangular shape because the 
relation between shear-strain threshold and horizontal PGV is not linear. These distributions fall 
into two groups depending on whether the UMT or LMT set of dynamic material property curves 
was used in the site response modeling. For the LMT grouping of distributions, shear strains 
associated with the shear-strain threshold distribution are generated at relatively lower ground 
motions (about 100 to 230 cm/sec). For the UMT grouping of distributions, higher ground 
motions (about 180 to 490 cm/sec) are needed to generate the shear-strain threshold level of 
shear strains. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 6-24 February 2005 
0.000 
0.002 
0.004 
0.006 
0.008 
0.010 
0.012 
0.014 
0.016 
0.018 
0.020 
0 100 200 300 400 500 600 
Horizontal Peak Ground Velocity (centimeters/second) 
Probability Density 
P1-UMT-1to2 Hz 
P1-LMT-1to2 Hz 
P2-UMT-1to2 Hz 
P2-LMT-1to2 Hz 
P1-UMT-5to10 Hz 
P1-LMT-5to10 Hz 
P2-UMT-5to10 Hz 
P2-LMT-5to10 Hz 
Source: Appendix D, Probability Distributions.xls. 
NOTE: In the legend, the notations refer to the various combinations of repository block velocity profile (P1, P2), 
dynamic material property curves (Upper Mean Tuff (UMT) and Lower Mean Tuff (LMT), and response 
spectrum frequency range (1to 2 Hz and 5 to 10 Hz). 
Figure 6-8. Probability Distribution of Bounding Horizontal PGV 
6.7 BOUND TO EXTREME GROUND MOTION AT YUCCA MOUNTAIN 
As discussed in Section 1, the characterizations of epistemic uncertainty and aleatory variability 
in the seismic hazard calculations show that, when extended to lower and lower annual 
frequencies of being exceeded, the ground motion level increases without bound, eventually 
reaching levels that are not credible and are physically unrealistic. In Section 6.6, an assessment 
is made of the bound to horizontal PGV experienced at the waste emplacement level at Yucca 
Mountain. Because the rocks at the emplacement level do not show evidence that this level of 
horizontal PGV has ever been achieved during the past 12.8 million years, the PGV probability 
distributions given in Section 6.6 are taken as a reasonable bound for use in TSPA. 
10 CFR 63.102(j) [DIRS 156605] provides that events (event classes or scenario classes) that 
are very unlikely (less than one chance in 10,000 over 10,000 years) can be excluded from the 
analysis. It is recognized that there are not sufficient data to prove that the bounding ground 
motions given in Section 6.6 have less than one chance in 10,000 of occurrence over 
10,000 years, such that they can be excluded from the TSPA per  63.102(j) [DIRS 156605]. 
However, during the 12.8 million years since deposition of the rocks at Yucca Mountain, there 
have been numerous opportunities for ground motions to exceed levels that would lead to rock 
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ANL-MGR-GS-000004 REV 00 6-25 February 2005 
deformation, if such motion were possible. The nearby Solitario Canyon fault, which is 
associated with recurrence intervals for large, surface-rupturing earthquakes of 35,000 to 
180,000 years (BSC 2004 [169734] Table 4-11), has experienced tens to hundreds of large 
earthquakes since the time the rocks were deposited. Further, other seismic sources in the 
region, which are included in the PSHA, also contribute to the potential for exceeding ground 
motions at the repository horizon, thereby further increasing the probability that extreme ground 
motions would have been achieved if they were possible. 
In defining event classes of input to performance assessment,  63.102(j) [DIRS 156605] calls 
for inclusion into the TSPA of credible events: An event class consists of all possible specific 
initiating events that are caused by a common natural process (e.g., the event class for seismicity 
includes the range of credible earthquakes for the Yucca Mountain site). The 12.8 million year 
geologic record at the Yucca Mountain site is considered to provide a reasonable basis for 
identifying what earthquakes are credible at Yucca Mountain. Specifically, it is reasonable to 
consider that earthquake ground motions that exceed what has been experienced in the last 
12.8 million years are not credible and should not be included in the TSPA. 
6.8 HAZARD CURVE FOR HORIZONTAL PEAK GROUND VELOCITY AT THE 
WASTE EMPLACEMENT LEVEL 
This section describes the development of a mean hazard curve for horizontal PGV at the waste 
emplacement level. The hazard curve reflects the bound to credible extreme ground motions that 
was presented in Sections 6.6 and 6.7. First, an unbounded mean hazard curve is developed 
based on horizontal PGV values determined from ground motion site-response modeling. Next, 
the probability distributions for the bounding value of PGV (Figure 6-8) are combined with the 
unbounded hazard curve to develop a composite mean hazard curve for horizontal PGV at the 
waste emplacement level. 
Ground motion site-response modeling determined values of horizontal PGV at the waste 
emplacement level for annual frequencies of exceedance of 10-4, 10-5, 10-6, and 10-7 (BSC 2004 
[DIRS 170027], Sections 6.3.1.1.3, 6.3.1.2.3, 6.3.1.4). These data 
(DTNs: MO0404PGVRL104.000 [DIRS 170437], MO0401SEPPGVRL.022 [DIRS 169099], 
MO0303DPGVB106.002 [DIRS 162712], and MO0210PGVPB107.000 [DIRS 162713]) 
provide direct input to the development of a hazard curve reflecting unbounded ground motion. 
The resulting hazard curve reflects unbounded ground motion because the site-response 
modeling was based on uniform hazard spectra from the PSHA for Yucca Mountain. The PSHA 
did not include an assessment of bounds for extreme ground motions. The hazard curve for 
unbounded horizontal PGV is constructed by using the site-specific values determined by the 
site-response analysis and interpolating or extrapolating to obtain values for other ground motion 
levels (Appendix D, Workbook Probability Distributions.xls, Worksheet Hazard Calcs). 
Interpolation and extrapolation is carried out using the logarithm of horizontal PGV and annual 
frequency of exceedance. 
To obtain a bounded hazard curve, the triangular distributions for the bounding value of PGV 
(Figure 6-8) are combined with the unbounded hazard curve to generate a new composite hazard 
curve for the repository horizon. The bounded ground motion exceeds a particular value, x, only 
if both the bounding value of PGV is greater than x and the ground motion from the original 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 6-26 February 2005 
unbounded analysis is greater than x. Mathematically, the annual frequency (hazard) that the 
composite PGV value is greater than a given value, x, is defined by the product of the probability 
that the bounding value for PGV has a value greater than x and the annual frequency that the 
original unbounded motion has a PGV value greater than x. This calculation methodology is 
implemented on worksheet Hazard Calcs in Microsoft Excel workbook Probability 
Distributions.xls (Appendix D). The process involves two steps. First, each of the 8 bounding 
horizontal PGV distributions is combined individually with the unbounded hazard curve for the 
waste emplacement level to produce eight modified mean hazard curves. Then for each value of 
horizontal PGV, the probabilities of the eight modified curves are averaged (arithmetic mean) to 
determine points on the final modified mean hazard curve (Figure 6-9). Equal weighting of the 
hazard curves is used to reflect the current assessment that the underlying cases representing 
epistemic uncertainty in site conditions are equally likely to represent actual conditions at Yucca 
Mountain. The unbounded hazard curve and the composite mean hazard curve reflecting the 
bound to horizontal PGV are shown in Figure 6-10. 
1.E-08 
1.E-07 
1.E-06 
1.E-05 
1.E-04 
10 100 1000 
Horizontal Peak Ground Velocity (cm/sec) 
Annual Probability of Exceedance 
Bounded [P1-UMT-1to2 Hz] 
Bounded [P1-LMT-1to2 Hz] 
Bounded [P2-UMT-1to2 Hz] 
Bounded [P2-LMT-1to2 Hz] 
Bounded [P1-UMT-5to10 Hz] 
Bounded [P1-LMT-5to10 Hz] 
Bounded [P2-UMT-5to10 Hz] 
Bounded [P2-LMT-5to10 Hz] 
Mean Bounded 
Source: Appendix D, Probability Distributions.xls. 
NOTE: The eight hazard curves result from combining the unbounded hazard curve with the eight triangular 
bounds to horizontal PGV. The eight triangular bounds represent epistemic uncertainty in the 
site-response modeling. The Mean Bounded curve represents the average of the other eight curves. 
Figure 6-9. Individual and Average Bounded PGV Hazard Curves for the Waste Emplacement Level 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 6-27 February 2005 
1.E-08 
1.E-07 
1.E-06 
1.E-05 
1.E-04 
10 100 1000 10000 
Horizontal Peak Ground Velocity (cm/sec) 
Annual Probability of Exceedance 
Unbounded 
Bounded 
Source: Appendix D, Probability Distributions.xls. 
Figure 6-10. Comparison of Horizontal PGV Hazard Curves for Bounded and Unbounded Ground 
Motion at the Waste Emplacement Level 

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ANL-MGR-GS-000004 REV 00 6-28 February 2005 
INTENTIONALLY LEFT BLANK
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 7-1 February 2005 
7. CONCLUSIONS 
Rock testing data, geologic data, and ground-motion site response data are combined to 
determine a bounding horizontal PGV. The analysis consists of four steps. First, laboratory 
testing and numerical simulations of lithophysal rock deformation are used to determine the 
shear-strain threshold for rock failure. Second, the results of the numerical simulations are 
combined with geologic observations in the ESF and ECRB Cross-Drift to conclude that the 
Topopah Spring Tuff lithophysal zones have not experienced shear-strains exceeding the 
threshold for failure. Third, ground-motion site response data are used to assess the level of 
horizontal PGV that would be required to generate shear strains exceeding the shear-strain 
threshold for failure. Fourth, it is concluded that such a level of horizontal PGV has not been 
reached at Yucca Mountain since the rocks were deposited 12.8 million years ago. 
Given the uncertainties in the available data, the bounding horizontal PGV is expressed as a 
probability distribution. A probability distribution is initially assessed for shear-strain threshold 
using a triangular distribution. It is then transformed into distributions for horizontal PGV on the 
basis of the ground-motion site-response modeling results. 
Laboratory testing results are used to assess a triangular distribution for shear-strain threshold 
with maximum and minimum values of 0.09% and 0.25%, respectively, and a modal value of 
0.16% (Figure 6-7). The range is based on the range determined from the laboratory testing 
results. The mode is assessed on the basis of the mean values determined for the laboratory 
samples with length-to-diameter ratios greater than 1.5. The range and mode determined from 
the laboratory testing results are consistent with results from the numerical simulations. 
To translate the shear-strain threshold probability distribution into a distribution for horizontal 
PGV at the waste emplacement level, the results of the ground-motion site-response modeling 
are used. Eight bounding horizontal PGV distributions are developed to account for the 
epistemic uncertainty in site-response modeling and the use of two response spectrum frequency 
ranges. The resulting distributions for horizontal PGV depart slightly from a triangular shape 
because the relation between shear-strain threshold and horizontal PGV is not linear. These 
distributions fall into two groups. In one group, the distributions range from about 100 to 
250 cm/sec and have a mode of about 175 cm/sec (Figure 6-8). In the other group, the 
distributions range from about 200 to 500 cm/sec and have a mode of about 335 cm/sec 
(Figure 6-8). 
A composite mean hazard curve, relating magnitude of horizontal PGV at the waste 
emplacement level to its annual frequency of exceedance, is determined by combining results of 
site-response modeling and the probability distributions for a bound to horizontal PGV at Yucca 
Mountain. First, a hazard curve for horizontal PGV is developed from site-response calculations 
for the waste emplacement level. These calculations reflect the unbounded mean uniform hazard 
spectra from the PSHA. Next, the hazard curve for unbounded motion is combined with the 
probability distributions for a bound to horizontal PGV. The resulting modified hazard curves 
are averaged to produce the composite mean hazard curve that reflects the assessed bound to 
extreme ground motions at Yucca Mountain (Figures 6-9 and 6-10). 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 7-2 February 2005 
These results have been submitted to the Technical Data Management System as product output 
and have DTN MO0501BPVELEMP.001. There are no restrictions on subsequent use of these 
data. 
Acceptance CriteriaThe work described in this report addresses acceptance criteria from the 
Yucca Mountain Review Plan, Final Report (NRC 2003 [DIRS 163274]). Relevant acceptance 
criteria are identified in Section 4.2. Table 7-1 lists the acceptance criteria and indicates how 
they have been addressed. 
Table 7-1. Summary of Applicable Yucca Mountain Review Plan, Final Report Acceptance Criteria and 
How They are Addressed in this Report 
Yucca Mountain Review Plan, Final Report 
Acceptance Criteria 
Summary of How Acceptance Criteria are Addressed 
in this Report 
Section 1.5.3: 
1. The General Information section of the license 
application contains an adequate description of 
site characterization activities. 
In accordance with part 1 of acceptance criterion 1, this 
report as a whole provides an description of the site 
characterization activity to develop a bound to horizontal 
PGV associated with extreme ground motion at Yucca 
Mountain. Geologic evidence (Section 6.3) is combined 
with rock mechanics results (Section 6.4) and ground 
motion results (Section 6.5) to establish the bound 
(Sections 6.6 and 6.7). Implications of the bound for 
seismic hazard at Yucca Mountain are presented in 
Section 6.8. 
2. The General Information section of the license 
applications contains an adequate description of 
site characterization results. 
In accordance with part 1 of acceptance criterion 2, 
Sections 6.3, 6.4, and 6.5 address the features and 
processes used to determine a bound for horizontal PGV 
associated with extreme ground motion at Yucca 
Mountain. 
In accordance with part 2 of acceptance criterion 2, 
Sections 6.6, 6.7 and 6.8 address the seismic ground 
motions that have the potential to occur in the future at 
Yucca Mountain. 
Section 2.2.1.2.2.3: 
1. Events are adequately defined. 
In accordance with part 1 of acceptance criterion 1, 
Section 6.8 addresses the mean annual frequency of 
exceedance for horizontal PGV at the waste emplacement 
level at Yucca Mountain. 
In accordance with part 2 of acceptance criterion 1, 
Sections 6.6 and 6.7 address how geologic analyses 
(Section 6.3) are combined with rock mechanics results 
(Section 6.4) and ground motion calculations (Section 6.5) 
to establish a geologically-based credible bound to 
horizontal PGV at the waste emplacement level for Yucca 
Mountain. 
2. Probability estimates for future events are 
supported by appropriate technical bases. 
In accordance with part 1 of acceptance criterion 2, 
Sections 6.6 and 6.7 address the development, based on 
inferred past patterns of ground motion, of a credible 
bound to horizontal PGV at the waste emplacement level 
for Yucca Mountain. Section 6.8 describes development of 
a hazard curve for horizontal PGV that reflects the bound. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 7-3 February 2005 
Table 7-1. Summary of Applicable Yucca Mountain Review Plan, Final Report Acceptance Criteria 
and How They are Addressed in this Report (Continued) 
Yucca Mountain Review Plan, Final Report 
Acceptance Criteria 
Summary of How Acceptance Criteria are Addressed 
in this Report 
3 Probability model support is adequate. In accordance with part 1 of acceptance criterion 3, the 
bound to horizontal PGV at the emplacement level for 
Yucca Mountain (Sections 6.6 and 6.7) and related hazard 
curve (Section 6.8) are developed on the basis of empirical 
observations (Sections 6.3 and 6.4) and numerical 
simulations (Sections 6.4 and 6.5). Rock mechanics 
simulations are calibrated using site-specific rock property 
data (Section 6.4). Site-specific geologic and geophysical 
data also form the basis for inputs to ground motion 
calculations (Section 6.5). The bound to horizontal PGV 
for extreme ground motions (Sections 6.6 and 6.7) is 
consistent with and based on conclusions regarding past 
ground motion events and processes at Yucca Mountain. 
4. Probability model parameters have been 
adequately established. 
In accordance with part 1 of acceptance criterion 4, the 
bound to horizontal PGV for extreme ground motion at 
Yucca Mountain is based on parameter values determined 
from site-specific geologic and geophysical data. Geologic 
data are discussed in Section 6.3, rock mechanics data are 
discussed in Section 6.4 and cited references, and ground 
motion data are discussed in Section 6.5 and cited 
references. 
5 Uncertainty in event probability is adequately 
evaluated. 
In accordance with part 1 of acceptance criterion 5, 
uncertainties are incorporated into the analysis by using 
probability distributions to characterize the bound to 
horizontal PGV at the waste emplacement level for Yucca 
Mountain (Sections 6.6 and 6.7). These uncertainties are 
taken into account in development of a bounded hazard 
curve for the waste emplacement level (Section 6.8). 
Uncertainties are also incorporated in the characterization 
of geologic evidence (Section 6.3), rock mechanics results 
(Section 6.4), and ground motion calculations (Section 
6.5). 
Section 2.2.1.3.2.3: 
2. Data are sufficient for model justification. 
In accordance with part 1 of acceptance criterion 2, 
Sections 6.3 through 6.8 provide the justification for 
establishing a credible bound for horizontal PGV at the 
waste emplacement level for Yucca Mountain. 
Descriptions of how the data were used and interpreted 
are provided in Sections 6.3 (geologic data), 6.4 (rock 
mechanics data), and 6.5 (ground motion data). The data 
are synthesized to develop a bound in Sections 6.6 and 
6.7 and a bounded hazard curve in Section 6.8. 
In accordance with part 3 of acceptance criterion 2, 
Sections 6.3 (geologic data), 6.4 (rock mechanics data), 
and 6.5 (ground motion data) discuss, or provide reference 
to, the techniques used in the analyses. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 7-4 February 2005 
Table 7-1. Summary of Applicable Yucca Mountain Review Plan, Final Report Acceptance Criteria 
and How They are Addressed in this Report (Continued) 
Yucca Mountain Review Plan, Final Report 
Acceptance Criteria 
Summary of How Acceptance Criteria are Addressed 
in this Report 
3. Data uncertainty is characterized and propagated 
through the model abstraction. 
In accordance with part 1 of acceptance criterion 3, 
Sections 6.6 and 6.7 provide the technical basis for the use 
of probability distributions to characterize the uncertainty in 
the bound to horizontal PGV for extreme ground motion at 
the waste emplacement level. Section 6.8 describes how 
the uncertainties are incorporated into a bounded hazard 
curve. Uncertainties in the evaluation of geologic data are 
presented in Section 6.3. Uncertainties in determination of 
a shear-strain threshold are discussed in Section 6.4. 
Uncertainties in ground motion calculations are provided in 
Section 6.5. 
In accordance with part 2 of acceptance criterion 3, 
Sections 6.3 through 6.8 provide the technical basis for a 
bounded hazard curve for horizontal PGV at the waste 
emplacement level within Yucca Mountain. This bound to 
extreme ground motion is based on site-specific data and 
analyses (Sections 6.3, 6.4, and 6.5); it is consistent with 
the geological observations at Yucca Mountain. 
In accordance with part 3 of acceptance criterion 3, 
Sections 6.3 (geologic data and analyses), 6.4 (rock 
mechanics data and analyses), and 6.5 (ground motion 
data and analyses) describe how uncertainty and variability 
are accommodated. Sections 6.6 and 6.7 describe the use 
of a probability distribution to incorporate these 
uncertainties into the development of a bound to horizontal 
PGV for the waste emplacement level at Yucca Mountain. 
Section 6.8 describes incorporation of the bound into a 
hazard curve for horizontal PGV. 
The analysis documented in this report is carried out to determine reasonable values of horizontal 
PGV at the waste emplacement level for annual frequencies of being exceeded considered in 
postclosure analyses. These are considered to be credible seismic inputs for TSPA, within the 
intent of  63.102(j) [DIRS 156605]. Based on the analyses presented, it is concluded that the 
bound to the horizontal PGV experienced at Yucca Mountain also provides a reasonable bound 
to credible ground motions for TSPA. 

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ANL-MGR-GS-000004 REV 00 8-1 February 2005 
8. INPUTS AND REFERENCES 
8.1 DOCUMENTS CITED 
170686 Abrahamson, N.A.; Bommer, J.J.; Strasser, F.O.; and Pecker, A. 2004. The 
Challenge of Defining Upper Bounds on Ground-Motion Parameters. Seismological 
Research Letters, 75, (2), 282-283. [El Cerrito, California: Seismological Society of 
America]. TIC: 256282. 
101425 Barton, C.C.; Larsen, E.; Page, W.R.; and Howard, T.M. 1993. Characterizing 
Fractured Rock for Fluid-Flow, Geomechanical, and Paleostress Modeling: Methods 
and Preliminary Results from Yucca Mountain, Nevada. Open-File Report 93-269. 
Denver, Colorado: U.S. Geological Survey. ACC: NNA.19931026.0008. 
170690 Brantley, S.R. 1996. Volcanoes of the United States. VOLCUS 1994. Denver, 
Colorado: U.S. Geological Survey, Information Services. Accessed July 14, 2004. 
ACC: MOL.20040902.0235. http://pubs.usgs.gov/gip/volcus/titlepage.html 
166660 BSC 2003. Subsurface Geotechnical Parameters Report. 
800-K0C-WIS0-00400-000-00A. Las Vegas, Nevada: Bechtel SAIC Company. 
ACC: ENG.20040108.0001. 
170027 BSC (Bechtel SAIC Company) 2004. Development of Earthquake Ground Motion 
Input for Preclosure Seismic Design and Postclosure Performance Assessment of a 
Geologic Repository at Yucca Mountain, NV. MDL-MGR-GS-000003 REV 01. 
Las Vegas, Nevada: Bechtel SAIC Company. ACC: DOC.20041108.0003. 
171850 BSC (Bechtel SAIC Company) 2004. Development of Seismic Inputs, Preparation of 
Seismic Topical Reports, and Evaluation of Disruptive Events Features, Events, and 
Processes. TWP-MGR-GS-000001 REV 03 ICN 02. Las Vegas, Nevada: Bechtel 
SAIC Company. ACC: DOC.20040923.0001. 
166107 BSC (Bechtel SAIC Company) 2004. Drift Degradation Analysis. 
ANL-EBS-MD-000027, Rev. 03. Las Vegas, Nevada: Bechtel SAIC Company. 
ACC: DOC.20040915.0010. 
172334 BSC (Bechtel SAIC Company) 2004. Lithophysal Rock Mass Mechanical Properties 
of the Repository Host Horizon. 800-K0C-SS00-00200-000-00A. Las Vegas, 
Nevada: Bechtel SAIC Company. ACC: ENG.20041111.0001. 
169183 BSC (Bechtel SAIC Company) 2004. Seismic Consequence Abstraction. 
MDL-WIS-PA-000003 REV 01. Las Vegas, Nevada: Bechtel SAIC Company. 
ACC: DOC.20041025.0004. 
169734 BSC (Bechtel SAIC Company) 2004. Yucca Mountain Site Description. 
TDR-CRW-GS-000001 REV 02 ICN 01. Two volumes. Las Vegas, Nevada: 
Bechtel SAIC Company. ACC: DOC.20040504.0008. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 8-2 February 2005 
103635 Budnitz, R.J.; Apostolakis, G.; Boore, D.M.; Cluff, L.S.; Coppersmith, K.J.; Cornell, 
C.A.; and Morris, P.A. 1997. Recommendations for Probabilistic Seismic Hazard 
Analysis: Guidance on the Uncertainty and Use of Experts. NUREG/CR-6372. Two 
volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. TIC: 235076; 
235074. 
162271 Buesch, D. 2003. Hydrogeologic Properties of Features in Crystallized Topopah 
Spring Tuff. E-mail from D. Buesch to D. Kicker and D. Rigby, March 10, 2003, 
with attachment. ACC: MOL.20030314.0188. 
170297 Buesch, D.C. and Lung, R.C. 2003. Tephrostratigraphic Relations and the Timing 
and Locations of Faulting Near Exile Hill at Yucca Mountain, Nevada. Proceedings 
of the 10th International High-Level Radioactive Waste Management Conference 
(IHLRWM), March 30-April 2, 2003, Las Vegas, Nevada. Pages 388397. 
La Grange Park, Illinois: American Nuclear Society. TIC: 254559. 
101433 Buesch, D.C. and Spengler, R.W. 1998. Character of the Middle Nonlithophysal 
Zone of the Topopah Spring Tuff at Yucca Mountain. High-Level Radioactive 
Waste Management, Proceedings of the Eighth International Conference, 
Las Vegas, Nevada, May 11-14, 1998. Pages 16-23. La Grange Park, Illinois: 
American Nuclear Society. TIC: 237082. 
104612 Buesch, D.C. and Spengler, R.W. 1998. Detailed Correlation of Lithostratigraphic 
and Borehole Geophysical Log Data for Identifying Contacts at Yucca Mountain. 
High-Level Radioactive Waste Management, Proceedings of the Eighth International 
Conference, Las Vegas, Nevada, May 11-14, 1998. Pages 248-251. La Grange Park, 
Illinois: American Nuclear Society. TIC: 237082. 
165483 Buesch, D.C.; Beason, S.C.; and Spengler, R.W. 1999. Relations Among Welding, 
Vapor-Phase Activity, Crystallization, and Fractures in the Tiva Canyon and Topopah 
Spring Tuffs, at Yucca Mountain, Nevada. Abstracts with Programs - Geological 
Society of America, 31, (7), A-476 - A-477. Boulder, Colorado: Geological Society 
of America. TIC: 254857. 
100106 Buesch, D.C.; Spengler, R.W.; Moyer, T.C.; and Geslin, J.K. 1996. Proposed 
Stratigraphic Nomenclature and Macroscopic Identification of Lithostratigraphic 
Units of the Paintbrush Group Exposed at Yucca Mountain, Nevada. Open-File 
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170697 Whelan, J.F. 2004. Secondary Mineral Deposits and Evidence of Past Seismicity and 
Heating of the Proposed Repository Horizon at Yucca Mountain, Nevada. 
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Inputs. SN-M&O-SCI-037-V3. Pages 1-77 Pages 72-125 
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Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 8-6 February 2005 
172106 YMP (Yucca Mountain Site Characterization Project) 1993. Preliminary Field 
Composite Borehole Log, Borehole ID: USW NRG-6. Las Vegas, Nevada: YMP 
(Yucca Mountain Site Characterization Office). ACC: DRC.19960509.0104. 
172113 YMP (Yucca Mountain Site Characterization Project) 1995. Composite Borehole 
Log, Borehole ID: USW UZ-14. Las Vegas, Nevada: Yucca Mountain Site 
Characterization Office. ACC: DRC.19960702.0263. 
172115 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Number: ECRB-THERMK-001. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010614.0098; MOL.20010207.0160. 
172116 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-002. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010614.0135; MOL.20010207.0160. 
172117 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-003. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010614.0103; MOL.20010207.0160. 
172118 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-004. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010614.0108; MOL.20010207.0160. 
172119 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-005. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010614.0113; MOL.20010207.0160. 
172121 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-006. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010913.0334; MOL.20010207.0160. 
172122 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-007. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010913.0339; MOL.20010207.0160. 
172124 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-008. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20010913.0344; 
MOL.20010207.0160. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 8-7 February 2005 
172131 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-009. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010913.0349; MOL.20010207.0160. 
172132 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-010. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010913.0354; MOL.20010207.0160. 
172136 YMP (Yucca Mountain Site Characterization Project) 2001. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-THERMK-011. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20010913.0359. 
172138 YMP (Yucca Mountain Site Characterization Project) 2003. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-012. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20030709.0313; 
MOL.20011015.0004. 
172141 YMP (Yucca Mountain Site Characterization Project) 2003. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-013. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20030709.0317; 
MOL.20011015.0004; MOL.20011206.0001. 
172143 YMP (Yucca Mountain Site Characterization Project) 2003. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-014. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20030709.0321; 
MOL.20011015.0004; MOL.20011206.0001. 
172145 YMP (Yucca Mountain Site Characterization Project) 2003. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-015. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20030709.0325; 
MOL.20011015.0004; MOL.20011206.0001. 
172146 YMP (Yucca Mountain Site Characterization Project) 2003. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-016. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20030709.0329; 
MOL.20011015.0004; MOL.20011206.0001. 
172149 YMP (Yucca Mountain Site Characterization Project) 2003. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-017. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20030709.0334; 
MOL.20011015.0004; MOL.20011206.0001. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 8-8 February 2005 
172150 YMP (Yucca Mountain Site Characterization Project) 2003. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-018. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20030709.0338; 
MOL.20011015.0004; MOL.20011206.0001. 
172151 YMP (Yucca Mountain Site Characterization Project) 2003. Sample Management 
Facility Geologic Log, Borehole Name: ESF-THERMK-019. [Las Vegas, Nevada: 
Yucca Mountain Site Characterization Office]. ACC: MOL.20030709.0343; 
MOL.20011015.0004; MOL.20011206.0001. 
172152 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ESF-GTEC-CS6500-01. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020703.0126; MOL.20011206.0001. 
172154 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ESF-GTEC-CS6500-01A. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020703.0130; MOL.20011206.0001. 
172155 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ESF-GTEC-CS 6500-02. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020703.0134; MOL.20011206.0001. 
172156 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ESF-GTEC-CS6500-04. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020703.0142; MOL.20011206.0001. 
172157 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ESF-GTEC-CS6500-04A. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020703.0146; MOL.20011206.0001. 
172158 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ESF-GTEC-CS6500-05A. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020703.0154; MOL.20011206.0001. 
172180 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ESF-GTEC-CS6500-05B. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020703.0158; MOL.20011206.0001. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 8-9 February 2005 
172181 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ESF-GTEC-CS6500-06. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020703.0162; MOL.20011206.0001. 
172183 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
and Drilling Department Geologic Log, Borehole Name: ECRB-GTEC-CS1600-08. 
[Las Vegas, Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20020710.0211; MOL.20011206.0001. 
172184 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
Facility Geologic Log, Borehole Name: ECRB-GTEC-CS1922-01. [Las Vegas, 
Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20021104.0116; MOL.20011206.0001. 
172185 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
Facility Geologic Log, Borehole Name: ECRB-GTEC-CS1928-01. [Las Vegas, 
Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20021104.0132; MOL.20011206.0001. 
172186 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
Facility Geologic Log, Borehole Name: ECRB-GTEC-CS1928-03. [Las Vegas, 
Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20021104.0140; MOL.20011206.0001. 
172187 YMP (Yucca Mountain Site Characterization Project) 2002. Sample Management 
Facility Geologic Log, Borehole Name: ECRB-GTEC-CS1995-01. [Las Vegas, 
Nevada: Yucca Mountain Site Characterization Office]. 
ACC: MOL.20021104.0145; MOL.20011206.0001. 
8.2 CODES, STANDARDS, REGULATIONS, AND PROCEDURES 
156605 10 CFR 63. Energy: Disposal of High-Level Radioactive Wastes in a Geologic 
Repository at Yucca Mountain, Nevada. Readily available. 
151802 YMP-USGS-GP-32, R2. Underground Geologic Mapping. [Denver, Colorado]: 
U.S. Geological Survey. ACC: MOL.19980930.0086. 
8.3 SOURCE DATA, LISTED BY DATA TRACKING NUMBER 
108396 GS990408314224.001. Detailed Line Survey Data for Stations 00+00.89 to 
14+95.18, ECRB Cross Drift. Submittal date: 09/09/1999. 
105625 GS990408314224.002. Detailed Line Survey Data for Stations 15+00.85 to 
26+63.85, ECRB Cross Drift. Submittal date: 09/09/1999. 
161910 GS021008314224.002. Lithophysal Data Study from the Tptpll in the ECRB from 
Stations 14+44 to 23+26. Submittal date: 01/28/2003. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 8-10 February 2005 
169591 GS040108314224.001. Detailed Line Survey Data for Horizontal and Vertical 
Traverses, ECRB. Submittal date: 02/27/2004. 
170312 GS040408314224.003. ESF, ECRB Cross Drift Small Scale Fracture Study: Detailed 
Line Survey Data for Horizontal and Vertical Traverses 2003. Submittal date: 
05/19/2004. 
171964 GS040808314224.005. Fractures in Slabs of Core in Crystallized Topopah Spring 
Tuff. Submittal date: 09/24/2004. 
153777 MO0012MWDGFM02.002. Geologic Framework Model (GFM2000). Submittal 
date: 12/18/2000. 
162713 MO0210PGVPB107.000. Design Peak Ground Velocity for the Repository Level 
(Point B) at 10-7 Annual Exceedance Probability. Submittal date: 10/17/2002. 
162712 MO0303DPGVB106.002. Design Peak Ground Velocity for the Repository Level 
(Point B) at 10-6 Annual Exceedance Probability. Submittal date: 03/10/2003. 
169099 MO0401SEPPGVRL.022. Peak Ground Velocity for the Repository Level (Point B) 
at 10-5 Annual Exceedance Frequency. Submittal date: 01/26/2004. 
172231 MO0402GSC04031.000. As-built ECRB Locations for the Tptpll Large Lithophysae 
Inventory, Tptpul-mn Lithophysal Maps and Traverses, and Small Scale Fracture 
Study. Submittal date: 02/25/2004. 
170437 MO0404PGVRL104.000. Peak Ground Velocity for the Repository Level (Point B) 
at 10-4 Annual Exceedance Frequency. Submittal date: 04/23/2004. 
172216 MO0409MWDGMMIO.000. Ground Motion Model Input and Output Files. 
Submittal date: 09/30/2004. 
161871 SN0208L0207502.001. Mechanical Properties of Lithophysal Tuff, Batch #1 (Test 
Dates: July 31, 2002 through August 16, 2002). Submittal date: 08/20/2002. 
161872 SN0211L0207502.002. Mechanical Properties of Lithophysal Tuff, Batch #2 (Test 
Dates: October 22, 2002 through October 25, 2002). Submittal date: 11/13/2002. 
163373 SN0305L0207502.005. Material Abundances from Point Counts on Laboratory 
Mechanical Property Specimens for Batch #1 and Batch #2. Submittal date: 
05/20/2003. 
8.4 SOFTWARE CODES 
161949 BSC (Bechtel SAIC Company) 2002. Software Code: UDEC. V3.1. PC 
WINDOWS 2000/NT 4.0. 10173-3.1-00. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 8-11 February 2005 
169930 BSC (Bechtel SAIC Company) 2004. Software Code: PFC2D. V 2.0. PC, Windows 
2000. 10828-2.0-01. 
167994 Dynamic Graphics 2000. Software Code: EARTHVISION. V5.1. SGI/IRIX 6.5. 
10174-5.1-00. 
163313 Pacific Engineering and Analysis. 2002. Software Code: NORM. V1.01. PC, 
DOS 6.22. 10386-1.01-00. 
170313 Pacific Engineering and Analysis. 2004. Software Code: LOGNORM. V 1.01. PC, 
DOS 6.22-QEMM 9.0. STN: 10384-1.01-00. 
8.5 OUTPUT DATA, LISTED BY DATA TRACKING NUMBER 
172682 MO0501BPVELEMP.001. Bounded Horizontal Peak Ground Velocity Hazard at the 
Repository Waste Emplacement Level. Submittal date: 01/11/2005. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 8-12 February 2005 
INTENTIONALLY LEFT BLANK 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 February 2005 
APPENDIX A 
GEOLOGIC LIMITS ON THE FORMATION OF FRACTURES IN THE 
LITHOPHYSAL AND NONLITHOPHYSAL ROCKS OF THE CRYSTAL-POOR 
MEMBER OF THE TOPOPAH SPRING TUFF 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 February 2005 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-1 February 2005 
A1. CONDITION OF TOPOPAH SPRING TUFF WITH RESPECT TO DAMAGE 
FROM EXTREME SEISMIC GROUND MOTION 
The condition of features such as lithophysae and fractures in the rocks of the Topopah Spring 
Tuff is a sum of the processes that have affected them since the time of formation, so if the 
features that result from specific processes can be identified, then the amount to which the 
features are developed can provide limits as to how active was a particular process. This linkage 
of understanding the formation of features to the timing and activity of respective processes can 
be used to develop a petrogenetic history of the rock. This petrogenetic history can, in turn, be 
used to evaluate and possibly set limits on the amount of damage done to the rock resulting from 
other specific processes such as seismic activity and specifically peak amounts of ground motion. 
The relationship of the observed physical condition of the rocks (for example, how fractured they 
are and when the fracturing occurred) to quantitative estimates of post-depositional strain relies 
on (1) the descriptive documentation of features in the rocks and (2) comparing these features 
with those predicted from rock mechanics measurements and modeling of stress and strain in the 
rocks. This section of Appendix A presents descriptions of the densely welded and crystallized 
rocks in the Topopah Spring Tuff, with an emphasis on the lithophysal and nonlithophysal rocks 
of the proposed repository host horizon (RHH) as defined by CRWMS M&O (1997 
[DIRS 100223], Section 7.3). The comparison of these features with the types of damage 
predicted by rock mechanics models and laboratory test results is presented in section 6.4 and 
Appendix B of this document. 
A1.1 DEVELOPMENT OF LITHOSTRATIGRAPHIC FEATURES 
The Topopah Spring Tuff is a large-volume (greater than 1,000 km3) pyroclastic flow deposit 
(also referred to as an ignimbrite) that was deposited 12.8 million years ago (Sawyer et al. 1994 
[DIRS 100075], Table 1), and as a result of depositional, welding, and crystallization processes, 
the formation is divided into members, zones, subzones, and intervals that form a stratiform 
deposit (Figure A1-1; Buesch et al. 1996 [DIRS 100106], p. 3). Depositional features include 
the distributions of lithic and pumice clasts, and the types and abundances of crystal fragments 
that are consistent with the compositional zonation from high-silica rhyolite in the lower part to 
the trachyte or quartz latite in the upper part of the ignimbrite (trachyte is used by Sawyer et al. 
(1994 [DIRS 100075], p. 1313) and quartz latite is used by Peterman and Cloke (2002 
[DIRS 162576], p. 685) and the difference is based on the type of classification system used). In 
Figure A1-1, the depositional features form the crystal-poor and crystal-rich members (crystal in 
this context refers to the amounts of crystal fragments). The zones of welding are based on 
(1) vitroclastic textures such as shapes and aspect ratios (where the aspect ratio is the long axis 
divided by the short axis) of glass shards and pumice clasts and (2) measured properties on core 
such as rock density and porosity. The Topopah Spring Tuff at Yucca Mountain is mostly 
(greater than 90 percent of the thickness) densely welded tuff (Buesch et al. 1999 
[DIRS 165483], p. A-476) with progressively less welded (moderately to partially welded and 
nonwelded) rocks near the top and bottom of the formation (Buesch et al. 1996 [DIRS 100106], 
p. 10). There are two sources of the interstitial vapor (that which is between the particles) at the 
time of deposition of an ignimbrite (Buesch et al. 1996 [DIRS 100106], p.12). The main source 
is from the vapor that exsolved from the magma during ascent in the conduit, in the eruption 
column, or during transportation of and deposition from the pyroclastic flow deposit. The other 
source is the inclusion of atmospheric air in the eruption column and during transportation of the 
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ANL-MGR-GS-000004 REV 00 A-2 February 2005 
pyroclastic flow. During welding, the redistribution of the vapor phase initially flowed through 
the compacting matrix, was later focused along fractures, and locally this redistribution resulted 
in development of lithophysal cavities (Buesch and Spengler 1998 [DIRS 101433], p.21). 
Source: Case and Buesch (2004 [DIRS 172099], p. 6). 
Figure A1-1. Lithostratigraphic Units (Members, Zones, Subzones, and Intervals) of the Topopah Spring 
Tuff at Yucca Mountain, Nevada, Showing the Equivalent Units of the Proposed Repository 
Host Horizon 
Crystallization of the Topopah Spring Tuff resulted from crystallization in the presence of vapor, 
in the absence of vapor, and from the vapor. During crystallization, the vapor-phase consists of 
the original interstitial vapor with progressive addition of vapor that exsolved from the glass 
particles as it crystallized (Smith 1980 [DIRS 106837] [reprint of U.S. Geological Survey 
Professional Paper 354-F (1960)], p. 153-156; Ross and Smith 1961 [DIRS 106714], p. 40; and 
Buesch et al. 1996 [DIRS 100106], p.12). This second source is from the magmatic water that 
did not exsolve from the magma (and glass) during the eruption and is the main source of 
volatiles described in some ignimbrites by Ross and Smith (1961 [DIRS 106714], p. 38). As the 
vapor contacted the glass, the two main processes were corrosion of the glass and crystallization 
of the glass in the presence of vapor. Corrosion can result (at least locally) in the almost 
complete preservation of the morphologic characteristics of the glass shards and pumice clasts by 
the secondary pore structure. Crystallization of glass in the presence of (but not from) the vapor 
phase results in the light gray to pinkish gray rims on lithophysae and fractures (Figure A1-2). In 
the rims, the grain sizes are typically larger than in the light reddish brown or reddish brown 
matrix-groundmass that shows no evidence of contact with the vapor phase. Rims typically are 
composed of elongate, needle-like, radiating, feldspar grains (many of which form spherulitic 
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textures) that appear to have nucleated on the cavity walls or on the crystallization front as it 
advanced away from the wall. Locally the feldspar grains in the spherulites are intergrown with 
one or more silica polymorphs (quartz, cristobalite, or tridymite). In some rims, tridymite grains 
appear to have grown around feldspar grains, and this relation is consistent with the in-filling of 
porous spherulites with vapor-phase mineralization. Crystallization of glass in the presence of 
vapor was probably facilitated by lowered viscosity of the glass resulting from re-absorption of 
water vapor (and other volatiles) from the vapor. Additionally, as the rims formed by 
crystallizing away from the cavity walls, the high porosity (0.30  0.10 cm3/cm3, Otto and 
Buesch 2003 [DIRS 170727], pp. 434-435) of the spherulitic rims enabled deeper penetration of 
the vapor into the host glass thereby propagating the crystallization of the rims. Some vapor 
gained access to the areas around the rims, possibly after formation of the rims, and resulted in 
crystallization of the grayish red purple borders and reddish gray matrix-groundmass 
(Figure A1-2, see figure for additional colors). In the areas farthest from lithophysae, the 
matrix-groundmass is typically reddish brown and is interpreted as crystallizing in the absence of 
vapor. The last stage of crystallization is mineralization from the cooling vapor, although 
exactly when in the cooling history of the ignimbrite this occurs is a result of the temperature, 
pressure, and composition of the vapor phase. The textural and inferred timing relations 
associated with lithophysae, including the sequence of localized concentration of the vapor phase 
that is surrounded by a rim, a border, reddish gray matrix-groundmass, and reddish brown 
matrix-groundmass farthest from the main concentration of vapor, and the vapor-phase mineral 
coatings on cavity walls are important constraints in the formation of lithophysae, but also are 
associated with many fractures (Figure A1-2). 
Fractures in the densely welded and crystallized ignimbrites of the Topopah Spring and 
Tiva Canyon Tuff are identified on the basis of crystallization and mineralization features as 
cooling fractures, which includes Type 1 and Type 2 fractures (Buesch et al. 1999 
[DIRS 165483], p. A-476) and post-cooling fractures, herein referred to as Type 3 fractures. 
Fractures with rims are interpreted as forming very early in the cooling history of the deposit 
during which the vapor in the fractures interacted with the glass along the walls of the fracture, 
and these fractures are indicative of Type 1 fractures (Buesch and Spengler 1998 
[DIRS 101433], p. 21; Buesch et al. 1999 [DIRS 165483], p. A-476). Tubular structures formed 
along some Type 1 fractures. Tubular structures consist of tubes that are typically 2-to-8-mm 
across (perpendicular to the plane of the host fracture), with a range of 0.5 to 21 mm, occur 
across several square meters of the fracture surface (in the plane of the host fracture), locally 
form intersecting patterns, and they have rims and vapor-phase mineral linings (Figure A1-3; 
Barton et al. 1993 [DIRS 101425], pp. 35 and 37). Early formation of tubular structures during 
the time when the deposit was glass also is indicated by the viscous droop of a septum between 
two tubular structures in a block from the Tiva Canyon Tuff (Figure A1-3). This block is not in 
place, but it has three planar fractures in which two are parallel and the central fracture is at 120 
to the other two, and all three fractures have well-developed tubular structures. On the central 
fracture, a small part of a septum between two tubes has a planar outer surface, which is the 
same as the main fracture face, but it has drooped as much as 1 cm into what must have been a 
fracture with at least a 1-cm aperture. This droop of the wall indicates the material inside the 
wall must have been viscous glass. In contrast, fractures that formed late in the cooling history 
of the deposit do not have rims, formed when the rock was mostly (if not entirely) crystallized, 
and these fractures are indicative of Type 2 fractures (Buesch and Spengler 1998 
[DIRS 101433], p.21; Buesch et al. 1999 [DIRS 165483], p. A-476). 
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Vapor-phase mineral coatings typically are on cooling fractures, but they are not necessarily on 
all cooling fractures because the fracture could have formed after most of the vapor phase had 
been removed from the area, or the three-dimensional network of fractures simply did not 
penetrate a region of abundant vapor phase material (Buesch and Spengler 1998 [DIRS 101433], 
p. 21). Although not previously described, fractures that formed after the rock had cooled to the 
ambient temperatures of a rock at the paleogeomorphic surface do not have vapor-phase mineral 
coatings, and these fractures are referred to as Type 3 fractures. So, vapor-phase mineral 
coatings can form on Type 1 and Type 2 fractures, but they do not form on Type 3 fractures. 
However, not all Type 2 fractures have vapor-phase mineral coatings, so the distinction of 
Type 2 and Type 3 fractures can be problematic, and other types of fracture data such as 
orientation, roughness, offset, trace length, and termination relations might be helpful in 
distinguishing the Type 2 and Type 3 fractures. One important corollary to this sometime 
difficult distinction of Type 2 and Type 3 fractures is that some fractures with no distinguishing 
features (which might be classified as Type 3) can be late-stage Type 2 fractures. In this paper, 
terms such as cooling refer to Type 1 and Type 2 fractures because the lithostratigraphic 
features such as rims or tubular structures and/or material that lines or fills the fracture are 
consistent with a fracture being formed during the cooling history of the deposit. The term 
indeterminate is used for fractures that do not have distinguishing features or fracture coating 
or fill material, so these fractures can be Type 3 or late-stage Type 2 fractures. 
Source: Case and Buesch (2004 [DIRS 172099], p. 5). 
NOTE: Porosity values for the matrix-groundmass are by Otto and Buesch (2003 [DIRS 170727], p. 435) 
approximated from Flint (1998 [DIRS 100033], Table 7) and Buesch (2003 [DIRS 162271], p. 2).The 
values for rims are from Otto and Buesch (2003 [DIRS 170727], p. 435), and the values for borders and 
vapor phase mineral coatings are estimates by Buesch (2003 [DIRS 162271], p. 2). Nomenclature and 
symbols of colors (e.g., pale red purple is 5RP6/2) are based on comparisons with the Munsell Soil Color 
Chart (Munsell Color Company 1994 [DIRS 106399]). 
Figure A1-2. Lithostratigraphic Features and Porosity of Lithophysae and Fractures in Densely Welded 
and Crystallized Tuff 
ANL-MGR-GS-000004 REV 00 A-5 February 2005 
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Source: This document. 
NOTES: A. Tubular structures on one of two fractures in the upper lithophysal zone (Tptpul) in Alcove 8. 
B. Block of Tiva Canyon Tuff with three cooling joints, each at 120 to the other and each with tubular structures. 
Each folding piece of the ruler is 23 cm long, and the magenta rectangle is the area in photograph C. 
C. Close up of central fracture with droop structure in a septum between tubes. 
Figure A1-3. Tubular Structures in the Topopah Spring and Tiva Canyon Tuffs 

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Lithostratigraphic features also are understood in the context of primary, secondary, and tertiary 
processes (Buesch and Spengler, 1998 [DIRS 101433], pp. 20-22; [DIRS 104612], pp. 248-249). 
Primary processes are processes that occur prior to deposition of the material and include the 
mechanics of eruption and the transportation and deposition of materials (and even processes in 
the magma chamber prior to eruption). Secondary processes are processes that occur from the 
moment of deposition to when the deposit attains ambient conditions at the paleogeomorphic 
surface and include compaction, welding, formation of lithophysae, crystallization, vapor-phase 
activity including corrosion and mineralization, fumarolic alteration, and development of cooling 
fractures. Also included as a secondary process is the moderate-temperature alteration of glass 
described by Levy and ONeil (1989 [DIRS 116960], p. 325). Tertiary processes are processes 
that occur after the deposit has attained ambient conditions at the paleogeomorphic surface (even 
millions of years or more) and include argillic and zeolitic alteration and fracturing resulting 
from structural deformation (faulting, flexing, and tilting) or tectonic disruption. 
In the context of the questions how did the rocks form and how might have the rocks been 
affected by post-depositional seismic events?, the important timing is the change from 
secondary to tertiary processes. There are no historic large-volume eruptions with which to 
compare the Topopah Spring Tuff, so the amount of time needed for a thick, large-volume 
ignimbrite to cool is poorly constrained. However, it might take several tens of years to perhaps 
a few hundred years after deposition, but about 100 years after deposition is probably a 
reasonable period of time. This estimate is based on (1) petrogenetic relations and processes 
such as those described in this report, (2) extrapolations of numerical modeling of welding in 
ignimbrites (Riehle et al. 1995 [DIRS 106671] , pp. 319, 325, and 326), and (3) an analogy with 
the Valley of Ten Thousand Smokes in Alaska. The 1912 eruption of the Alaskan Novarupta 
volcano resulted in pyroclastic flow deposits that might be as great as 200-m thick and formed 
the Valley of Ten Thousand Smokes (Brantley, 1994 [DIRS 170690], p. 7); however, the ten 
thousand smokes in the ignimbrite sheet mostly died out by 1930 (Wood and Kienle, 1990 
[DIRS 125616], p. 70). 
A1.1.1 Characteristics and Timing of Fracture Development in Crystallized Rocks 
Two studies were conducted that help quantify the (1) timing of when various features formed in 
the densely welded and crystallized rock of the Topopah Spring Tuff, (2) fracture characteristics 
of the lithophysal and nonlithophysal zones of the Topopah Spring Tuff, and (3) timing of 
fracture development. These studies focused on the mineral and textural relations that provide 
constraints for evaluating the development of fracture, and the geometric relations of fractures 
such as orientation, planarity, and terminations have not been evaluated as part of this study. 
The Fractures in slabs study is a detailed examination of a wide variety of lithostratigraphic 
features associated with fractures that have been mapped on slabs of core. The map scale is such 
that measurements can be made to 0.1 mm or less. This study evokes the most recent 
understanding of features associated with crystallization of the tuff. The second study 
re-examines the Detailed Line Survey (DLS) data on fractures in the Enhanced Characterization 
of the Repository Block (ECRB) Cross-Drift. The DLS data examined in this study was 
collected in two stages. The first stage was done as the tunnel was being cut and consists of 
fractures that intersected the DLS transect and have a minimum trace length of 1 m, and these 
data are for the total length of the ECRB Cross-Drift. The second stage was the Small-Scale 
Fracture (SSF) Study in which fractures with no minimum trace length were documented along 
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6-m long transects and each location also had three 2-m long vertical transects. For both the total 
ECRB Cross-Drift and SSF data, the minimum recorded measurements for separation across 
shears and faults is 1 cm, and the minimum recorded measurements of fracture aperture and 
widths of mineral coatings on the fracture wall or material filling a fracture is 0.5 mm, although 
terms such as trace, spotty, and patchy also are used. The main emphasis of the total 
ECRB Cross-Drift and SSF DLS studies were to document the geometric relations of fractures 
such as location, orientation (strike and dip), planarity and roughness, and truncation relations. 
Identification and measurement of mineral coatings and fracture material fill was routinely done; 
however, this was of secondary importance during data collection and this gives rise to some 
small, but not quantifiable, amount of uncertainty to the fracture fill data. However in this study, 
the values reported by the geologists are assumed to be correct. 
Data from the DLS re-examination study that support this document are provided in two 
Microsoft Excel workbooks (Appendix D). These workbooks are PGV ECRB DLS 
Frac-Fill.xls and PGV SSF DLS Frac-Fill.xls. These workbooks contain additional data and 
various graphical displays that are not presented in this document. 
A1.1.1.1 Fractures in Slabs of Core 
Samples for mapping of fractures on slabs of core were collected from two surface-based 
boreholes (including USW NRG-6 and USW UZ-14) and 32 tunnel-based boreholes (included 
Thermal-K and Geotechnical boreholes) located in the Exploratory Studies Facility (ESF) 
Main-Drift and the ECRB Cross-Drift (Figure A1-4; Table A1-1). These boreholes were used to 
collect samples that represent different lithostratigraphic zones, spatial variations within the 
zones, samples from different sizes of core, and samples that can be compared to those collected 
near the tunnel walls (i.e., to evaluate any induced fractures from the tunnel borehole machine). 
Samples are from ten lithostratigraphic zones and subzones in the Topopah Spring Tuff 
(Table A1-2). Rocks from the upper lithophysal and lower lithophysal zones tend to have more 
samples than other zones because (1) these zones (or at least parts of them) comprise the 
Repository Host Horizons, and (2) the lithophysal zones have some of the larger textural and 
structural variations compared to nonlithophysal zones. 
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Table A1-1. Boreholes from which Core Samples were Collected 
Borehole 
Borehole-Sample 
Short Identifier 
Station or 
Northing1 Easting 
Diameter of 
Core2 (mm) 
Number 
of 
Samples3 
USW NRG-6 NRG6 766726.500 564187.000 61 mm 5 
USW UZ-14 UZ14 771309.812 560141.562 61 mm 39 
ECRB ThermK-001 ThermK 1562.2  45 mm 4 
ECRB ThermK-002 ThermK 1569.9  45 mm 4 
ECRB ThermK-003 ThermK 1527.98  45 mm 2 
ECRB ThermK-004 ThermK 1528.70  45 mm 2 
ECRB ThermK-005 ThermK 1529.46  45 mm 4 
ECRB ThermK-006 ThermK 1539.84  45 mm 2 
ECRB ThermK-007 ThermK 1541.24  45 mm 2 
ECRB ThermK-008 ThermK 1542.56  45 mm 2 
ECRB ThermK-009 ThermK 1737.7  45 mm 2 
ECRB ThermK-010 ThermK 1745.4  45 mm 2 
ECRB ThermK-011 ThermK 1745.5  45 mm 2 
ESF ThermK-012 ThermK 5789.9  45 mm 2 
ESF ThermK-013 ThermK 5782.1  45 mm 2 
ESF ThermK-014 ThermK 5781.9  45 mm 2 
ESF ThermK-015 ThermK 5782.8  45 mm 2 
ESF ThermK-016 ThermK 6336.9  45 mm 2 
ESF ThermK-017 ThermK 6329.2  45 mm 2 
ESF ThermK-018 ThermK 6330.1  45 mm 2 
ESF ThermK-019 ThermK 6330.5  45 mm 2 
ESF-GTEC-CS6500-01 GTEC 6360.0  289 mm 1 
ESF-GTEC-CS6500-01A GTEC 6360.0  289 mm 3 
ESF-GTEC-CS6500-02 GTEC 6368.8  289 mm 2 
ESF-GTEC-CS6500-04 GTEC 6391.4  289 mm 1 
ESF-GTEC-CS6500-04A GTEC 6396.0  289 mm 4 
ESF-GTEC-CS6500-05A GTEC 6386.0  289 mm 1 
ESF-GTEC-CS6500-05B GTEC 6384.0  289 mm 1 
ESF-GTEC-CS6500-06 GTEC 6369.0  289 mm 2 
ECRB-GTEC-CS1600-08 GTEC 1634.0  289 mm 4 
ECRB-GTEC-CS1922-01 GTEC 1922.2  289 mm 2 
ECRB-GTEC-CS1928-01 GTEC 1928.47  289 mm 9 
ECRB-GTEC-CS1928-03 GTEC 1928.7  289 mm 1 
ECRB-GTEC-CS1995-01 GTEC 1995.9  289 mm 1 
1 Coordinates (in feet) for USW-NRG-6 and USW UZ-14 are from the TDMS GI database, station locations (in meters) of the 
ThermK boreholes are from SN-SNL-SCI-024-V1 Howard (2002 [DIRS 159152], pp. 136, 145), and SN-SNL-SCI-024-V2 
(Sanchez and Howard 2004 [DIRS 172401], p. 121), and station locations (in meters) of the GTEC boreholes are from the 
Sample Management and Drilling Department Geologic Logs (See Section A2 for specific citations). Note that USW NRG-6 
and USW UZ-14 are Surface-Based Boreholes, and ThermK and GETC are Tunnel-Based Boreholes. 
2 The diameters for cores and the stations in the tunnels (in meters) for the ThermK and GETC boreholes are from the Sample 
Management and Drilling Department Geologic Logs (See Section A2 for specific citations). 
3 Detailed sample listings in DTN: GS040808314224.005 [DIRS 171964]. 

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Source: Simplified from Day et al. 1998 [DIRS 101557]. 
NOTE: Borehole coordinates and station positions in the tunnels are in Table A1-1, station locations for ECRB 
Panel Maps and Photographs are in Sections A3 and A4, and ECRB DLS in Table 4-1 of this report. 
Northing and Easting coordinates are in feet and are referenced to the Nevada State Plane, Central Zone 
[Horizontal Datum is NAD 27]. The area of waste emplacement (BSC 2004 [DIRS 172334], Figure 1-3) is 
outlined by the blue line. 
Figure A1-4. Locations of Surface-Based Boreholes, and Tunnel-Based Boreholes, Detailed Line Survey 
Data, and Panel Maps and Photographs in the Enhanced Characterization of the 
Repository Block Cross-Drift 
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Table A1-2. Number of Core Samples in Lithostratigraphic Zones and Subzones of the Topopah Spring 
Tuff 
Lithostratigraphic unit Symbol1 Short symbol Unit number2 
Number of 
samples 
Crystal-rich member Tptr 
Vitric zone Tptrv 
Densely welded subzone Tptrv1 rv1 8.2 2 
Nonlithophysal zone Tptrn rn 7.0 6 
Lithophysal zone Tptrl 
Crystal-rich subzone Tptrl2 rl2 6.4 1 
Transition subzone Tptrl1 rl1 6.2 1 
Crystal-poor member Tptp 
Upper lithophysal zone 
(ThermK) 
Tptpul*TK pul*TK 5.2 8 
Upper lithophysal zone Tptpul pul 5.0 32 
Middle nonlithophysal zone Tptpmn 
Transition subzone Tptpmn4 pmn4 4.4 4 
Upper nonlithophysal subzone Tptpmn3 pmn3 4.3 1 
Lower lithophysal zone 
(ThermK) 
Tptpll*TK pll*TK 3.2 36 
Lower lithophysal zone Tptpll pll 3.0 19 
Lower nonlithophysal zone Tptpln pln 2.0 7 
Vitric zone Tptpv 
Densely welded subzone Tptpv3 pv3 1.6 3 
1 Lithostratigraphic names and symbols are from Buesch et al. (1996 [DIRS 100106], Table 2) and Buesch and 
Spengler (1998 [DIRS 101433], p. 16). 
2 Unit number is arbitrarily assigned to zones and subzones with the smallest number for the deepest units. Unit 
number is only used for plotting or sorting of data on the basis of lithostratigraphic zone or subzone. The 
ThermK samples have a unique number because they are from small-diameter core samples. 
Source: DTN: GS040808314224.005 [DIRS 171964] 
Fractures are categorized on the basis of features related to cooling history (rims and vapor-phase 
mineral coating, etc.) and those that are indeterminate where there are no features to constrain 
the timing of formation (Table A1-3). Cooling-related fractures are divided into 4 categories 
based on how well rims and vapor-phase mineral coating on the fractures are developed. Three 
other cooling-related features include annealed fractures that formed as a discontinuity but 
crystallized back together, veinlets and streaks (where veinlets can also be categorized as one of 
the rim and vapor-phase mineral coated categories), and fractures with dusky red or reddish 
purple borders. Fractures with no cooling features are categorized as being indeterminate, 
although as discussed in Section A-1.1, some of these indeterminate fractures can be late-stage 
cooling fractures. Fractures with very fined-grained black minerals (possibly manganese or iron 
oxides) are categorized as being indeterminate because these minerals might be deposited from 
water that moved along the fractures, and it is difficult to know when this deposition occurred. 
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Table A1-3. Categories of Fractures Based on Development of Features Related to Cooling of the 
Deposit or Indeterminate Timing of Formation 
Symbol Color Description 
Cooling related fractures (0 to 100 years after deposition) 
VPLm-w, R Cyan Vapor-phase lining (VPL) is moderately to well developed, Rims 
(R) are well developed. 
VPLp, Rp Green VPL and R are poorly developed. 
VPLhair Deep Blue VPL in (fills) hairline fractures 
VPLn, Rp Chartreuse No VPL, Rims or borders are poorly developed. 
VPLn, Rn, An Brown No VPL or R, but fracture is annealed. 
Veinlet Magenta Veinlet (pathways of vapor-phase transport) that has VPL. 
Streak Magenta Fracture (many are incipient) with rim material, but no VPL. 
P or B border Gold Purple or brown borders on fractures, but with no VPL. 
Indeterminate fractures (timing not constrained) 
VPLn, Rn Black No VPL or R and no other mineral lining, so the timing of fracture 
formation is indeterminate. 
B min Red Black mineral deposits along fracture surface (presumably 
Manganese or Iron oxides), so the timing of fracture formation is 
indeterminate. 
Source: DTN: GS040808314224.005 [DIRS 171964] 
Maps of slabs depict the 10 fracture categories and geometric relations of the fractures 
(Figure A1-5). Four typical relations are demonstrated in the maps in Figure A1-5. 
1. Many fractures are of a single category; however, some fractures have different 
crystallization characteristics along their trace. Typically, variations occur along fractures in 
the development of the rims or vapor-phase mineral coatings. 
2. Some fractures have trace lengths that transect the core; however, many fractures have trace 
lengths and terminations completely within the core. For fractures that are longer than the 
core, the true trace length is not known and the recorded length is a truncated value. 
3. Some fractures intersect or terminate at other fractures, whereas many fractures terminate in 
the rock. Fracture intersections and terminations occur at angles ranging from acute, to 90, 
to obtuse. Some fractures have several splays that either bifurcate or reconnect to form an 
anastomosing pattern. 
4. Although the maps are at a scale where features less than 1 mm can be identified, fractures 
rarely have evidence of separation across them. Fractures do not have evidence of 
mechanical degradation such as brecciation or rounding of corners formed at the intersection 
of fractures. 
Fractures related to cooling of the deposit typically are more numerous than indeterminate 
fractures, although individual slabs can have more indeterminate fractures than cooling fractures 
(Figure A1-6). Of the 2022 fractures mapped in the densely welded and crystallized rocks of the 
Topopah Spring Tuff, 69.7 percent (1410 fractures) are cooling related fractures and 30.3 percent 
(612 fractures) are indeterminate, although these indeterminate fractures might also have formed 
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during the late stage of cooling. These relations also are represented by the cooling to 
indeterminate ratio (C/I ratio) for each sample where the total number of cooling fractures are 
divided by the total number of indeterminate fractures (Figure A1-7). A C/I ratio of 1 indicates 
there are equal numbers of cooling and indeterminate fractures in a sample; a ratio larger than 1 
indicates there are proportionately more cooling fractures than indeterminate fractures; and a 
ratio smaller than 1 indicates there are proportionately less cooling fractures than indeterminate 
fractures. The C/I ratio is plotted by sample (Figure A1-7a) or as a distribution function for each 
lithostratigraphic unit (Figure A1-7b). For lithostratigraphic units with greater than 5 samples, 
there is an asymmetric distribution of the C/I ratios with cooling fractures being more abundant 
than indeterminate fractures; thereby, indicating a strong influence by stresses induced during 
cooling on the formation of fractures. To calculate the C/I ratio and avoid division into or by 
0, if there are no cooling or indeterminate fractures in a sample, then a value of 0.1 is assigned 
to that type of fracture in that sample. 
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a) 
b) 
Source: DTN: GS040808314224.005 [DIRS 171964], Readme.doc file, pages 8-9. 
NOTES: a. Slab from the upper lithophysal zone at a depth of 714.1 ft in USW UZ-14. 
b. Slab from the middle nonlithophysal zone (specifically the upper nonlithophysal subzone) at a depth of 732.2 ft in USW UZ-14. Color codes for 
fractures are listed in Table A1-3 and Figure A1-6. 
Figure A1-5. Fracture Maps of Core from Boreholes USW UZ-14 and Therm-K-005 and Therm-K-007 
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ANL-MGR-GS-000004 REV 00 A-14 February 2005 
c) 
d) 
Source: DTN: GS040808314224.005 [DIRS 171964]. 
NOTES: c. Slab from the lower lithophysal zone at a depth of 0.4 ft in Therm-K-007. 
d. Slab from the lower lithophysal zone at a depth of 40.1 ft in Therm-K-005. Color codes for fractures are listed in Table A1-3 and Figure A1-6. 
Figure A1-5. Fracture Maps of Core from Boreholes USW UZ-14 and Therm-K-005 and Therm-K-007 (continued) 

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ANL-MGR-GS-000004 REV 00 A-15 February 2005 
Source: DTN: GS040808314224.005 [DIRS 171964]. 
NOTE: Symbols of categories and lithostratigraphic units are in Tables A1-2 and A1-3. 
Figure A1-6. Number of Fractures Displayed by Category and Lithostratigraphic Zone or Subzone in the Densely Welded and Crystallized 
Topopah Spring Tuff 
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Source: DTN: GS040808314224.005 [DIRS 171964]. 
NOTES: a. C/I ratios of individual samples plotted by lithostratigraphic zone or subzone. Symbols for 
lithostratigraphic units are in Table A1-2. 
b. The number of C/I ratio values in 5x10x increments plotted by lithostratigraphic zone or subzone. Lines 
are only plotted for units with 5 or more samples. 
Figure A1-7. Cooling to Indeterminate Ratio (C/I Ratio) of Fractures by Lithostratigraphic Zone or 
Subzone in the Densely Welded and Crystallized Topopah Spring Tuff 
The number of fractures per unit area (cm2) of slab varies by lithostratigraphic zone and subzone 
with the (1) larger values in the deepest part of the section and (2) the lower lithophysal zone 
having the larger individual values (Figure A1-8a). These trends are similar where the fractures 
are divided into fractures longer than 1 cm and especially for those that are shorter than 1 cm 
(Figure A1-8b and c). Similar relations of the total area and total fractures per total area 
compared to the lithostratigraphic zone or subzone also indicate that the lower parts of the 
section, especially the lower lithophysal zone, have more fractures per unit area than the upper 
parts of the section (Figure A1-9). Because there are only a few samples from lithostratigraphic 
units other than the upper and lower lithophysal zones, some bias to the data is possible. These 
fractures-per-area relations indicate that the various lithostratigraphic units responded differently 
in the formation of fractures and support the stratiform characterization of fractures. 
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Source: DTN: GS040808314224.005 [DIRS 171964]. 
NOTES: a. Total number of fractures per cm2 of slab by lithostratigraphic units. Symbols for lithostratigraphic units are in Table A1-2. 
b. Number of fractures greater than 1-cm long per cm2 of slab by lithostratigraphic units. 
c. Number of fractures less than 1-cm long per cm2 of slab by lithostratigraphic units. 
Figure A1-8. Variation in the Numbers of Fractures Per Area (cm2) of Slab by Lithostratigraphic Zone and Subzone in the Densely Welded and 
Crystallized Topopah Spring Tuff 
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Source: DTN: GS040808314224.005 [DIRS 171964]. 
NOTE: Symbols for lithostratigraphic units are in Table A1-2. 
Figure A1-9. Total Area of Samples and Total Number of Fractures Per Total Area (cm2) of Slab by 
Lithostratigraphic Zone and Subzone in Slabs of Core from the Densely Welded and 
Crystallized Topopah Spring Tuff 
In most tunnel-based ThermK and GTEC boreholes, the relative amounts of cooling fractures 
and indeterminate fractures are consistent in samples near the tunnel wall with those from near 
the end of the borehole; however, in some boreholes the amounts differ (Figure A1-10). These 
relations occur regardless of the rocks being in the upper or lower lithophysal zones. In addition 
to documenting some of the local variations in fractures, the relative abundance of cooling and 
indeterminate fractures in tunnel-based boreholes indicates a lack of evidence of fractures 
induced by the tunnel-boring machine. 
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Source: DTN: GS040808314224.005 [DIRS 171964]. 
NOTE: Symbols for lithostratigraphic units are in Table A1-2. 
Figure A1-10. Fractures in Slabs of Core from the Thermk and GTEC Boreholes Plotted by Depth in the 
Borehole, Number of Cooling (C) and Indeterminate (I) Fractures Per Sample, and 
Lithostratigraphic Zone in Which Each Borehole Is Located 
A1.1.1.2 Detailed Line Surveys in the ECRB Cross-Drift 
DLS data on fractures in the ECRB focused on geometric relations of the fractures; however, 
other features such as rims developed on fracture walls and material coating or filling the 
fractures also were documented. In 1998, DLS data in the ECRB were collected for 1810 
discontinuities in 2,664 m of tunnel (DTNs: GS990408314224.001 [DIRS 108396] and 
GS990408314224.002 [DIRS 105625]; Mongano et al. 1999 [DIRS 149850]), and these data are 
included in the Microsoft Excel 97 workbook PGV ECRB DLS Frac-Fill.xls that is part of the 
supporting data files for this report (Appendix D). Fractures in the DLS are classified as 
non-genetic Fracture (F) (i.e., those not identified as being in any other category), Vapor-phase 
parting (VPP), Cooling joint (CJ), Shear (SH), Shear zone (SHZ), Fault (FLT), and Fault zone 
(FZ) with an additional category of Not applicable (NA) typically referring to conditions 
obscuring features on the walls and other comments. For this classification of discontinuities, 
vapor-phase partings are shallowly dipping with long trace lengths; cooling joints were identified 
primarily on the geometric relations of long trace length and planarity; shears and shear zones 
have separation across the feature of less than 0.1 m; and faults and fault zones have separations 
equal to or greater than 0.1 m. Using this classification of discontinuities, 80.7 percent are 
non-genetic fractures with only 11.2 percent related to cooling features (vapor-phase partings 
and cooling joints), 8.0 percent related to shears or faults, and 0.1 percent as not applicable 
(recorded as rubble zones) (Figure A1-11a). 
Five types of features are used to identify cooling fractures including crystallization features 
such as rims and vapor-phase mineral linings, tubular structures (sometimes shortened to simply 
tubes), and macroscopic features such as vapor-phase partings and cooling joints that are 
identified primarily on the basis of geometric relations (dip angle, trace length, planarity, etc.). 
Some fractures have more than one of these features; for example, 1010 fractures have only 
1 feature, 203 have 2 features, 73 fractures have 3 features, 1 fracture has 4 features, and no 
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fractures have 5 features. Of the types of features, vapor-phase mineral linings comprise 
76.0 percent of the data, rims are 10.3 percent, tubular structures are 1.3 percent, vapor-phase 
partings are 4.9 percent, and cooling joints are 7.5 percent (Figure A1-12). 
Material coatings or fillings of fractures, shears, and faults are products of various processes, so 
these materials are used to categorize fractures in terms of a petrogenetic history. The coatings 
or fillings are described with 15 categories and symbols including No fill or Not applicable 
(NA), Broken or crushed rock or sand (Br), Breccia (Bx), Calcite (C), Clay (Ar), Fault gouge 
(Fg), Fault rubble (Fr), Iron oxides (Io), Manganese (M), Opal (O), Silica (amorphous) (S), 
Quartz (Q), Vapor-phase lining (V), Unknown (U), and Zeolites (Z). Some of these material 
coatings or fillings are grouped into similar categories such as the C,O,S,Q category where 
calcite and opal, silica, and quartz are grouped because these minerals are typically deposited by 
water moving along the fractures (although some of the SiO2 polymorphs might have been 
deposited from cooling of the vapor phase), and the Misc. category includes manganese oxide 
(the most abundant mineral), iron oxides, and unknown materials that are probably deposited 
from aqueous solutions that flowed along the fracture.. Using these categories of material fill, 
49.2 percent have vapor-phase linings, 17.4 percent are Misc. (mostly as manganese oxide), 
12.9 percent have no fill, 7.5 percent are C,O,S,Q, 0.4 percent have clay fill (or partial fill), 
and 12.6 percent are broken rock (or sand), breccia, fault gouge, or fault rubble (although 
11.2 percent of this category is broken rock or sand) (Figure A1-11b). 
Shears, shear zones, faults, and fault zones are associated with broken rock (or sand), breccia, 
fault gouge, or fault rubble (fault gouge and fault rubble are only identified in faults or fault 
zones). However, the broken rock (or sand) also occurs in numerous fractures that are not shears 
or faults. This one way correlation relation of shears and faults to broken rock (or sand), 
breccia, rubble, or gouge is consistent with the fact that there are only 145 shears and faults 
(Figure A1-11a) whereas there are 318 occurrences of broken rock (or sand), breccia, rubble, or 
gouge (Figure A1-11b). Numerous shears and some fractures and shears filled with broken or 
crushed rock or sand have cooling related features such as rims and tubular structures, but in the 
currently used classification, these features were not included in the categorization. 
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Source: PGV ECRB DLS Frac-Fill.xls (Appendix D). 
NOTES: The numbers of fractures are below the symbol and the percent of the total is at the bottom 
a. Fracture types. 
b. Fracture lining or filling material. 
c. Re-categorized fractures and fill material (figure a) on the basis of cooling and "non-cooling" 
(indeterminate) fractures. 
Figure A1-11. Abundance of Fracture (Discontinuity) Types and Fillings in the ECRB Cross-Drift from 
Detailed Line Survey Data 
Using the cooling and indeterminate fractures and broken or crushed rock or sand fracture-fill 
categorization scheme for fractures, 61.2 percent are cooling related fractures with only 
24.9 percent having no diagnostic textural evidence as to when or how it formed (although these 
might be late-stage cooling fractures), and 13.9 percent having broken or crushed rock or sand 
material filling the fractures (Figure A1-11c). Of the broken or crushed rock or sand fill 
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material, 8.4 percent is associated with vapor-phase minerals, 0.4 percent is associated with clay, 
and 5.1 percent is in discontinuities with no or other mineral fillings. One interesting relation 
resulting from this re-examination of mineral fill is that the clay-filled fractures occur with 
broken or crushed or sand material, and this association reinforces the sedimentary deposition 
mechanism proposed by Buesch and Lung (2003 [DIRS 170297]). 
Source: PGV ECRB DLS Frac-Fill.xls (Appendix D). 
NOTE: Some values do not total to 100 percent as a result of rounding. The numbers of fractures are below the 
symbol and the percent of the total is at the bottom. Each type of feature was counted individually, and 
some fractures contain more than one of these features, so the total features (1639) is greater than the 
cooling fractures and broken or crushed rock or sand filled fractures associated with vapor-phase 
mineral linings. 
Figure A1-12. Abundance and Percent of Discontinuities in the ECRB DLS Data with Cooling Related 
Features Such as Rims, Tubular Structures (Tubes), or Vapor-Phase Mineral Linings (V-P 
Lining), or Identified During Logging as Vapor-Phase Partings (VPP) or Cooling Joints (CJ) 
Focusing on just the discontinuities filled with broken or crushed rock or sand, 68.2 percent 
are in non-genetic fractures, 29.1 percent are in shears, shear zones, faults, or fault zones, and 
only 2.8 percent are in cooling joints (Figure A1-13a). This association of broken or crushed 
rock or sand fill material with discontinuities having some amount of separation across them 
(i.e., shears, shear zones, faults, and fault zones) is not necessarily a surprise. However, it is 
interesting that most of the broken or crushed rock or sand fill material is associated with 
non-genetic fractures. This second relation with non-genetic fractures indicates that the fractures 
simply opened and dilated to form apertures large enough for the broken or crushed or sand 
material to fill the fracture. With respect to material fill associated with the broken or crushed 
rock or sand filled fractures, 53.8 percent have vapor-phase minerals, 27.8 percent have Misc. 
minerals (mostly manganese oxide), 12.2 percent have C,O,S,Q, 2.5 percent have clay, and 
3.7 percent are breccia, fault gouge, or fault rubble (Figure A1-13b). For the vapor-phase 
minerals to be identified, and not specified as clasts, it is assumed that the vapor-phase minerals 
are intact coatings or linings on the fracture walls. The integrity of the vapor-phase mineral 
linings and the 71.0 percent of discontinuities being non-genetic or cooling joints (from 
Figure A1-13a) also indicates most of the fractures simply dilated rather than resulting from 
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appreciable shear. These discontinuity-type and material-fill relations for broken or crushed or 
sand filled discontinuities are similar to the general discontinuity population (Figure A1-11a 
and b), especially the fractures filled with vapor-phase minerals and the Misc. and C,O,S,Q 
minerals. 
Source: PGV ECRB DLS Frac-Fill.xls (Appendix D). 
NOTE: Some values do not total to 100 percent as a result of rounding. The numbers of fractures are below the 
symbol and the percent of the total is at the bottom. 
Figure A1-13. Discontinuities in the ECRB DLS Data that are Filled with Broken or Crushed Rock or 
Sand Compared to (a) Discontinuity Type and (b) Fill Material 
The DLS data from the ECRB indicates that of the originally documented discontinuities, only 
8.0 percent are related to shears or faults (and 0.1 percent as not applicable that is actually two 
rubble zones) (Figure A1-11a), so 91.9 percent provide evidence for the petrogenetic 
development of fractures. The reclassified DLS discontinuity data indicates that 61.2 percent are 
cooling related fractures, 24.9 percent are indeterminate as to how or when they formed 
(although these might be late-stage cooling fractures), and 13.9 percent have broken or crushed 
rock or sand material filling the fractures (Figure (A1-11c). However, when the fractures or 
shears filled with broken or crushed rock or sand material are not included, 71.1 percent of the 
fractures are cooling related and 28.9 percent have no diagnostic features to indicate how or 
when they formed (i.e., are indeterminate) (Figure (A1-11c). When the fractures or shears 
with broken or crushed rock or sand material are focused on (and normalized to 100 percent), 
61.3 percent are associated with vapor-phase minerals and 38.7 percent are indeterminate in 
formation and are either not associated with other materials or are associated with clay, calcite 
and opal, silica, and quartz (C,O,S,Q ) or manganese oxide, iron oxides, and unknown 
materials (Misc.). Although the proportions of cooling and indeterminate fractures differ 
by only about 10 percent, comparison of fractures with and without broken or crushed rock or 
sand material indicate that many cooling and indeterminate fractures were simply dilated. A 
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few of these fractures with broken or crushed rock or sand material might have been used to 
form some of the shears and faults, although some shears and faults might have formed 
independently of these pre-existing fractures. 
In contrast to the total DLS data along the entire ECRB Cross-Drift, where only fractures greater 
than 1 m in length were included, the Small-Scale Fracture (SSF) Study used the same 
techniques as the DLS but the fractures measured have no minimum length. The Small-Scale 
Fracture Study consists of 14 locations along the ECRB Cross-Drift with 2 locations in the upper 
lithophysal zone, 2 locations in the middle nonlithophysal zone, 9 locations in the lower 
lithophysal zone, and 1 location in the lower nonlithophysal zone. The configuration of a SSF 
location includes a 6-m long horizontal traverse that replicates the position of the original DLS 
data, and three, vertical, 2-m long traverses positioned (one each at the end of the horizontal 
traverse and one in the middle). The SSF DLS data from the ECRB Cross-Drift are from the 
data package DTN: GS040108314224.001 [DIRS 169591] and GS040408314224.003 
[DIRS 170312], and these data are included in the Microsoft Excel 97 workbook 
PGV SSF DLS Frac-Fill.xls that is part of the supporting data files for this report (Appendix D). 
As with the original total ECRB Cross-Drift DLS data, the Small-Scale Fracture DLS data has 
been analyzed and re-categorized with similar results, although the proportion of specific 
features differ with the result that there are approximately equal amounts of cooling and 
indeterminate fractures (48.9 percent and 51.1 percent, respectively) 
(PGV SSF DLS Frac-Fill.xls in Appendix D). Using the original classification of discontinuities 
and comparing the SSF to the total DLS, approximately the same percent of non-genetic 
fractures were identified; however, there were more cooling features (vapor-phase partings and 
cooling joints) and fewer shears (and no faults) (Figure A1-14a). Using the categories of 
material fill, in the SSF data there are slightly fewer vapor-phase mineral linings, about three 
times as many no fill fractures, and about the same amount of fractures filled with broken 
rock or sand (Figure A1-14b). For fractures identified as cooling fractures, in the SSF data 
there are about the same percentage of rims and tubular structures, slightly fewer vapor-phase 
mineral coated, many more vapor-phase partings, and slightly fewer cooling joints 
(Figure A1-15). Using the cooling and indeterminate fractures and broken or crushed rock or 
sand fracture-fill categorization scheme for fractures, in the SSF data there are fewer cooling 
fractures, more no fill or not diagnostic (indeterminate) fractures, and only slightly fewer 
broken or crushed rock or sand material filling the fractures (Figure A1-14c) than observed 
from the DSL data (Figure A1-11c). 
Focusing on just the discontinuities filled with broken or crushed rock or sand, almost all are 
non-genetic fractures with cooling joints as the next abundant (but very small) category 
(Figure A1-16a). With respect to material fill associated with the broken or crushed rock or 
sand filled fractures, the vast majority have vapor-phase minerals (Figure A1-16b), so the 
vapor-phase mineral lined fractures appear to be preferentially popped open. 
The one obvious difference in the SSF and total DLS data is the SSF data has fewer cooling and 
more indeterminate fractures (48.9 percent and 51.1 percent, respectively in the SSF data versus 
71.1 percent and 28.9 percent, respectively in the total ECRB data) (Figures A1-14c and 
A1-11c). The differences in the cooling versus indeterminate ratio, which is 1.0 for the SSF data 
and 2.5 for the total ECRB data, might result from the large difference in the lengths of traverses 
sampled (only 168 m in the SSF compared to 2,664 m in the total ECRB). Another contributing 
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factor in the differences in the cooling versus indeterminate ratios in the SSF and total DLS data 
might be the relative amounts of data in each lithostratigraphic unit. For example, in the SSF 
data there are 14.3 percent in the upper lithophysal zone (Tptpul), 14.3 percent are in the middle 
nonlithophysal zone (Tptpmn), 64.3 percent are in the upper lithophysal zone (Tptpll), and 
7.1 percent are in the lower lithophysal zone (Tptpln) whereas in the total ECRB data there are 
41.2 percent are in the Tptpul, 16.1 percent are in the Tptpmn, 33.1 percent are in the Tptpll, and 
9.6 percent are in the Tptpln. 
Source: PGV SSF DLS Frac-Fill.xls (Appendix D). 
NOTES: The numbers of fractures are below the symbol and the percent of the total is at the bottom. 
a. Fracture types. 
b. Fracture lining or filling material. 
c. Re-categorized fractures and fill material (figure a) on the basis of cooling and "non-cooling" 
(indeterminate) fractures. 
Figure A1-14. Abundance of Fracture Types and Fillings in the ECRB from Small-Scale Fracture DLS 
Data 
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Source: PGV SSF DLS Frac-Fill.xls (Appendix D). 
NOTE: The numbers of fractures are below the symbol and the percent of the total is at the bottom. Each type of 
feature was counted individually, and some fractures contain more than one of these features, so the total 
features (1616) is greater than the cooling fractures and broken or crushed rock or sand filled fractures 
associated with vapor-phase mineral linings. 
Figure A1-15. Abundance and Percent of Discontinuities in the ECRB Small-Scale Fracture DLS Data 
with Cooling Related Features Such as Rims, Tubular Structures (i.e., Tubes), or 
Vapor-Phase Mineral Linings (V-P Lining), or Identified During Logging as Vapor-Phase 
Partings (VPP) or Cooling Joints (CJ) 
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Source: PGV SSF DLS Frac-Fill.xls (Appendix D). 
NOTE: The numbers of fractures are below the symbol and the percent of the total is at the bottom. 
Figure A1-16. Discontinuities in the ECRB Small-Scale Fracture DLS Data that are Filled with Broken 
or Crushed Rock or Sand Compared to (a) Discontinuity Type and (b) Fill Material 
The four types of discontinuities (including shears, shear zones, faults, and fault zones) identified 
in the DLS data in the ECRB Cross-Drift (Mongano et al. 1999 [DIRS 149850] p. 48) provide 
constraints on how the rock mass has deformed. Shears and shear zones have less than 0.1 m of 
separation and faults and fault zones have 0.1 m or greater separation. Where features such as 
pumice or lithic clasts or lithophysae are truncated by a discontinuity, but the matching part of 
the feature cannot be identified on the opposite side of the discontinuity, the amount of 
separation is undeterminable and the discontinuity is identified as a shear. Of the 
1810 discontinuities in the ECRB Cross-Drift, 107 (5.9 percent) are shears, 4 (0.2 percent) are 
shear zones, 29 (1.6 percent) are faults, and 5 (0.3 percent) are fault zones (Figure A1-11a). The 
shear and fault data provide insights on the small- and large-scale deformation of the rock mass. 
1. On the small scale  The technical procedure for data collection (YMP-USGS-GP-32, 
R2, [DIRS 151802] Section 5.2.13) uses examples of separations measured to the 
nearest decimeter and indicates smaller separations can be recorded in centimeters, but 
a minimum separation is not described. Of the shears and shear zones, 50 are 
designated as Unknown separation and 57 have separations from 1 to 9 cm, so 
empirically, the minimum resolution for separation recorded in the ECRB DLS data is 
1 cm (PGV ECRB DLS Frac-Fill.xls in Appendix D). 
2. On the large scale  Of the 1810 discontinuities in the ECRB, only 8.0 percent have 
measured separation of greater than 1 cm, and this is consistent with deformation of 
the mountain-scale rock mass by concentration of shear along relatively few 
discontinuities (PGV ECRB DLS Frac-Fill.xls in Appendix D). 
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A1.1.1.3 Summary of Characteristics and Timing of Fracture Development in 
Crystallized Rocks 
Data from the fractures in slabs of core and DLS were collected for different reasons and 
represent different scales of sample size and resolution; however, they form a consistent set of 
relations (1) in the general petrogenetic formation of the cooling features of fractures, (2) where 
about 70 percent of fractures are related to cooling and 30 percent are indeterminate (but might 
be late-stage cooling related), and (3) where the vast majority of fractures have no evidence of 
shear or mechanical degradation. On the basis of how well features such as rims, borders, and 
vapor-phase mineral coatings are developed, features related to cooling are identified as early 
or Type 1 and late-stage or Type 2. Type 1 and 2 fractures were originally defined with 
multiple criteria including trace length, planarity, and the development of rims, borders, and 
vapor-phase mineral coatings (Buesch et al., 1999 [DIRS 165483]). Type 1 fractures formed 
during the time that the host rock was glass, and although not well constrained, this was probably 
within the first 5 to 15 years after deposition of the Topopah Spring Tuff. Type 2 fractures 
formed during the time that the host rocks had crystallized but had not cooled to the ambient 
temperature of a rock near the ground surface, and again this is not well constrained, but was 
probably in the range of 10 to 100 years (Buesch and Spengler, 1998 [DIRS 101433], p. 21). 
Detailed small-scaled studies such as those on slabs of core (and observations in thin sections) 
and the Small-Scale Fracture studies indicate that although trace length and planarity are 
important properties, the development of rims, borders, and vapor-phase mineral coatings are the 
defining characteristics. With this shift in defining characteristics, there are a few refinements to 
the Type 1 and Type 2 definitions. Type 1 is retained for the general category, and for fractures 
with trace lengths that are measured on length scales of greater than 1 m. Type 1s is used for 
fractures with rims, borders, and tubular structures, and for fractures with trace lengths that are 
measured on length (or partial length) scales of less than 1 m. Vapor-phase mineral coatings can 
be on Type 1 and 1s fractures, but they are not necessarily part of the defining characteristics 
because the amount of vapor needed to form these deposits might not have been locally available 
during the appropriate temperatures for mineralization. Similarly, Type 2 is retained for the 
general category, and for fractures with trace lengths that are measured on length scales greater 
than 1 m. Type 2s is used for fractures without rims, borders, and tubular structures but with 
vapor-phase mineral coatings, and for fractures with trace lengths that are measured on length (or 
partial length) scales of less than 1 m. Vapor-phase mineral coatings are important for 
identifying Type 2 and 2s fractures because without the rims, borders, and tubular structures, the 
vapor-phase mineral coatings are one of the only ways to distinguish cooling fractures from 
Type 3 fractures that formed after cooling of the deposit. 
In the DLS data, the ratio of cooling and indeterminate features is not exactly the same in 
fractures, shears, and broken or crushed rock or sand material filled discontinuities. However, 
the overall proportions of cooling and indeterminate features in these different discontinuities are 
consistent with the formation of an intricate, early formed, fracture network. A subset of this 
early formed network of cooling and indeterminate (but possibly cooling related) fractures 
were opened by (1) dilation of the fractures during thermal contraction and cooling of the rock 
mass or (2) extension during structural tilting or faulting. Broken or crushed rock or sand 
material filled some fractures and shears (and even some faults). The vast majority of these 
fractures and shears appear to have formed under the simple conditions of tension and without 
significant evidence of compression or large amounts of dynamic grinding, shaking, or 
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chattering of the discontinuities. This lack of significant evidence of compression or large 
amounts of dynamic grinding, shaking, or chattering of the fractures is consistent with the 
fracture relations in the slabs of core. 
It is important to note that this fairly simple tensional deformation history does not necessarily 
apply to all shears or faults in the repository block of Yucca Mountain for three reasons: 
1. The review and re-categorization of the ECRB DLS data focused on the fractures and 
shears in the main rock mass and did not include detailed analyses of the larger faults 
and fault zones (especially the Solitario Canyon fault); 
2. The internal granular texture, fabric, structure, and architecture of shears and faults 
have not been studied in detail to determine amounts of mechanical abrasion of 
fragments. Many shears and small faults have relatively simple characteristics; 
however, some faults with larger amounts of separation (including the Solitario 
Canyon fault) appear to have grading in grain sizes that increases away from the wall. 
This grain structure is consistent with either size sorting during flow of granular 
materials (i.e., sedimentary processes such as grain flow along an open fault plane), 
or segregation and grading resulting from shear and possibly mechanical abrasion and 
grain-size reduction resulting from shear (i.e., mechanical processes); and 
3. The ECRB Cross-Drift transected several faults typical of many faults at Yucca 
Mountain, including the Solitario Canyon fault, so there is probably a good 
representation of fault characteristics in the ECRB data; however, not all the faults at 
Yucca Mountain have been examined. 
A1.1.2 Shapes of Lithophysae as Large Strain Indicators 
Discontinuum numerical model results of drift stability for some 10-5 and all 10-6 annual 
frequency of exceedance ground motion simulations indicate the drift walls and surrounding 
rocks of the lower lithophysal zone in the Topopah Spring Tuff become pervasively shattered 
resulting in collapse of the drift (BSC, 2004 [DIRS 166107] Section 6.4.2.2). In contrast, 
modeling runs for 10-4 and some of the 10-5 annual frequency of exceedance ground motion 
simulations did not result in pervasive shattering of the rocks and therefore, no collapse of the 
drift (BSC, 2004 [DIRS 166107] Section 6.4.2.2). Discontinuum numerical modeling including 
lithophysal cavities (Section 6.4.2) suggests that lithophysae would be extensively damaged, and 
possibly collapsed at high shear strains. 
To look for field evidence of collapsed lithophysae, locations in the ECRB Cross-Drift have been 
re-examined where photographs of the walls document the conditions of the rocks in the lower 
lithophysal, middle nonlithophysal, and upper lithophysal zones (Table A-4). To support 
lithophysal studies in 2001 and 2002, 18 photographs (each photograph includes an area of about 
1.4x4.2 m of the tunnel wall) were taken and served as the base-maps for the Panel Maps 
(DTN: GS021008314224.002 [DIRS 161910]). The 1x3-m sized panel maps document the size, 
shape, and abundance of lithophysae and other features such as spots and lithic clasts (with no 
minimum size), and the features were mapped in the field at a scale of 1:10 with a minimum 
resolution of about 1 mm. However, use of the digital images for the panel maps provide 
photographic interpretive scales of features as small as 2 mm. To support fracture and 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-30 February 2005 
lithophysal studies in 2003 and 2004, 20 photographs (each includes about 2.3x7.4 m of the 
tunnel wall) were taken to document locations of the 2x6-m sized Small-Scale Fracture and 
Panel Photograph study locations. Of these 20 photographs, 14 were taken on opposite walls of 
the tunnel to form pairs of photographs at seven stations. The digital images of the 2x6-m areas 
provide photographic interpretive scales of features as small as 2 mm, and lithophysae with 
diameters larger than 20 cm were documented. Photographs for the Panel Maps, Small-Scale 
Fracture, and Panel Photographic study locations were taken with low-angle illumination to 
accentuate the edges of cavities. 
Table A1-4. Locations (Including Station and Wall), Lithostratigraphic Zones, and Sizes of Photographs 
of Tunnel Walls in the ECRB Cross-Drift, Including the Primary Study for which the 
Photographs were Taken and List of the Section in which the Photograph is Displayed 
Station Wall 
Lithostratigraphic 
Zone 
Photograph 
Size (m) 
Nominal 
Size (m) Primary Study 
Photograph 
Name Section 
06+60 Left Tptpul 2.3x7.4 2x6 Small Scale Fracture 
study 
PP0660L A4 
06+60 Right Tptpul 2.3x7.4 2x6 Panel photograph study PP0660R A4 
07+40 Left Tptpul 2.3x7.4 2x6 Panel photograph study PP0740L A4 
07+40 Right Tptpul 2.3x7.4 2x6 Panel photograph study PP0740R A4 
08+15 Left Tptpul 2.3x7.4 2x6 Panel photograph study PP0815L A4 
08+16 Right Tptpul 2.3x7.4 2x6 Panel photograph study PP0816R A4 
09+10 Left Tptpul 2.3x7.4 2x6 Panel photograph study PP0910L A4 
09+10 Right Tptpul 2.3x7.4 2x6 Panel photograph study PP0910R A4 
09+35 Left Tptpul 2.3x7.4 2x6 Panel photograph study PP0935L A4 
09+35 Right Tptpul 2.3x7.4 2x6 Panel photograph study PP0935R A4 
10+35 Left Tptpmn 2.3x7.4 2x6 Small Scale Fracture 
study 
PP1035L A4 
10+35 Right Tptpmn 2.3x7.4 2x6 Panel photograph study PP1035R A4 
12+20 Left Tptpmn 2.3x7.4 2x6 Panel photograph study PP1220L A4 
12+18 Right Tptpmn 2.3x7.4 2x6 Panel photograph study PP1218R A4 
14+93 Right Tptpll 1.4x4.2 1x3 Panel map study PM1493R A3 
15+51 Left Tptpll 1.4x4.2 1x3 Panel map study PM1515L A3 
16+10 Right Tptpll 1.4x4.2 1x3 Panel map study PM1610R A3 
16+24 Right Tptpll 1.4x4.2 1x3 Panel map study PM1624R A3 
16+41 Left Tptpll 1.4x4.2 1x3 Panel map study PM1641L A3 
16+41 Right Tptpll 1.4x4.2 1x3 Panel map study PM1641R A3 
16+56 Left Tptpll 1.4x4.2 1x3 Panel map study PM1656L A3 
17+26 Left Tptpll 1.4x4.2 1x3 Panel map study PM1726L A3 
17+68 Left Tptpll 1.4x4.2 1x3 Panel map study PM1768L A3 
17+68 Right Tptpll 1.4x4.2 1x3 Panel map study PM1768R A3 
18+05 Left Tptpll 1.4x4.2 1x3 Panel map study PM1805L A3 
18+05 Left Tptpll 2.3x7.4 2x6 Small Scale Fracture 
study 
SSF1805L A4 
18+86 Left Tptpll 1.4x4.2 1x3 Panel map study PM1886L A3 
18+86 Left Tptpll 2.3x7.4 2x6 Small Scale Fracture 
study 
SSF1886L A4 
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ANL-MGR-GS-000004 REV 00 A-31 February 2005 
Table A1-4. Locations (Including Station and Wall), Lithostratigraphic Zones, and Sizes of 
Photographs of Tunnel Walls in the ECRB Cross-Drift, Including the Primary Study for 
which the Photographs were Taken and List of the Section in which the Photograph is 
Displayed (Continued) 
Station Wall 
Lithostratigraphic 
Zone 
Photograph 
Size (m) 
Nominal 
Size (m) Primary Study 
Photograph 
Name Section 
19+19 Left Tptpll 1.4x4.2 1x3 Panel map study PM1919L A3 
19+20 Left Tptpll 2.3x7.4 2x6 Small Scale Fracture 
study 
SSF1920L A4 
20+18 Left Tptpll 1.4x4.2 1x3 Panel map study PM2018L A3 
20+19 Left Tptpll 2.3x7.4 2x6 Small Scale Fracture 
study 
SSF2019L A4 
20+69 Left Tptpll 1.4x4.2 1x3 Panel map study PM2069L A3 
20+71 Left Tptpll 2.3x7.4 2x6 Small Scale Fracture 
study 
SSF2071L A4 
21+24 Left Tptpll 1.4x4.2 1x3 Panel map study PM2124L A3 
21+25 Left Tptpll 2.3x7.4 2x6 Small Scale Fracture 
study 
SSF2125L A4 
22+32 Left Tptpll 1.4x4.2 1x3 Panel map study PM2232L A3 
22+94 Left Tptpll 1.4x4.2 1x3 Panel map study PM2294L A3 
Source: DTN: GS021008314224.002 [DIRS 161910], DTN: MO0402GSC04031.000 [DIRS 172231], and 
Sections A3 and A4 of this report. 
Prior to the lithophysal studies conducted from 2001 to 2003, three basic shapes (simple, 
merged, and cuspate) of lithophysae had been identified and were incorporated into the recent 
studies, and during the 2001-2002 mapping effort a fourth category (expansion-crack 
lithophysae) was identified (Figure A1-17). The simple, merged, and expansion-crack 
lithophysae shapes are entirely consistent with the growth and inflation of cavities during 
welding and redistribution of the vapor phase. Cuspate lithophysae typically merge with one or 
more fractures or veinlets along cusps, and this shape is consistent with the partial deflation of 
the cavity after being breached by a propagating fracture. As the lithophysal studies continued 
from 2001 to 2003 (and 2004), it became clear that some cuspate lithophysae might be parts of 
expansion-crack lithophysae, although these lithophysae were not re-examined in detail and 
possibly re-categorized. For lithophysal cavities to inflate (and some deflate), the host material 
must have been viscous and ductile; therefore, it was glass. Where the vapor in the cavities 
interacted with the glass, it formed a rim that is typically composed of elongate feldspar minerals 
and either quartz or cristobalite. Being composed of minerals, a rim could not deform as a cavity 
inflated, so the rim typically formed a series of small expansion cracks that broke the wall into 
several curviplanar plates that moved apart as the cavity inflated. These small expansion cracks 
typically do not penetrate much beyond the edge of the rim or into matrix-groundmass, although 
some merge with veinlets or streaks and small fractures. Expansion-crack lithophysae formed in 
a similar way as other lithophysae, except that a few propagating expansion cracks were the 
dominant mechanism by which the cavity inflated, and the walls of the cavity between the 
expansion cracks simply moved away from the center of the lithophysae and from the opposite 
side of the expansion crack. Some lithophysae, especially expansion-crack lithophysae, appear 
to have some expansion cracks that merge into a discontinuous network of circum-lithophysal 
fractures that might represent the final stages of decoupling of the rigid rim and the ductile 
matrix. 
ANL-MGR-GS-000004 REV 00 A-32 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: Panel maps in DTN: GS021008314224.002 [DIRS 161910] and Section A3 of this report. 
NOTES: a. Simple lithophysae. 
b. Simple lithophysae with expansion cracks. 
c. Merged lithophysae. 
d. Expansion-crack lithophysae. 
Figure A1-17. Shapes of Lithophysae 
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ANL-MGR-GS-000004 REV 00 A-33 February 2005 
Panel Maps include the location and shape of lithophysal cavities, rims on lithophysae, spots, 
and lithic clasts (Figure A1-18). During the mapping of features on the Panel Maps, individual 
shapes of features were mapped on the 1:10 scale photographs and several types of 
measurements (including the shape category) were recorded in Microsoft Excel workbooks 
with Meas (for Measurements) in the file title (DTN: GS021008314224.002 [DIRS 
161910]). A full set of 18 electronic (JPEG) files of panel maps is included in Section A3. 
Eleven 2x6-m photographs were used for photographic interpretations of lithophysal shapes 
where lithophysae greater than 20 cm in diameter were inventoried (Figure A-19). A full set of 
20 electronic (JPEG) files of panel photographs are included in Section A4. Although the walls 
of the tunnel were initially washed just after they were cut by the tunnel boring machine (TBM) 
and before they were mapped for the Full Periphery Maps and Detailed Line Surveys by the 
Bureau of Reclamation, numerous lithophysae were backfilled by muck from the TBM. 
During data collection on the panel maps, backfilled lithophysae were dug out by geologists; 
however, on the 2x6-m panel photographs the backfilled lithophysae were simply identified as 
such, especially if the shape could not be determined. In addition to identifying the four initial 
(simple, merged, cuspate and expansion-crack) shapes of lithophysae, data such as backfilled 
and collapsed lithophysae and those transected by fractures or shears have also been compiled 
for lithophysae identified in the panel maps and photographs. These data are included in a 
Microsoft Excel 97 workbook PGV Lithop Shapes ECRB.xls (Appendix D). 

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ANL-MGR-GS-000004 REV 00 A-34 February 2005 
Source: Panel maps in DTN: GS021008314224.002 [DIRS 161910] and Section A3 of this report. 
NOTE: Complete panel map at station location 16+41 on the left rib. Lithophysal cavities are labeled in red with red lines outlining the cavity and green lines 
outlining the rim. Spots are labeled in cyan with outlines in cyan. Lithic clasts are labeled in orange and outlined in orange. These panel maps were 
designed to be viewed electronically or printed on 11x17-inch paper. 
Figure A1-18a. Example Panel Map of Lithophysal Cavities, Lithophysal Rims, Spots, and Lithic Clasts 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-35 February 2005 
Source: Panel maps in DTN: GS021008314224.002 [DIRS 161910] and Section A3 of this report. 
NOTE: Panel map at station location 21+25 on the left rib with photograph and mapped features displayed separately. Lithophysal cavities are labeled in red 
with red lines outlining the cavity and green lines outlining the rim. Spots are labeled in cyan with outlines in cyan. Lithic clasts are labeled in orange 
and outlined in orange. 
Figure A1-18b. Example Panel Map of Lithophysal Cavities, Lithophysal Rims, Spots, and Lithic Clasts (Continued) 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-36 February 2005 
Source: Section A4 of this report. 
NOTES: Lithophysal cavities greater than 20 cm in diameter are labeled in cyan, the yellow circle is 20 cm in diameter, and red-painted lines are fractures 
greater than 1 m in length that were mapped as part of the Detailed Line Survey. 
a. Panel photograph at station location 07+40 on the left rib in the upper lithophysal zone. Four lithophysae (indicated by magenta arrows) are either 
transected by fractures or the fractures terminate at the lithophysae. 
b. Panel photograph at station location 18+86 on the left rib in the lower lithophysal zone. The red rectangle is the 1x3-m sized area of the associated 
panel map. Lithophysae in the panel map are not included in this photograph, but are displayed in the panel map in Section A3. 
Figure A1-19. Panel Photographs with Locations of Lithophysal Cavities Greater Than 20 cm in Diameter that were Inventoried for Shape and 
Possible Collapse Features 
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ANL-MGR-GS-000004 REV 00 A-37 February 2005 
Source: Section A4 of this report. 
NOTE: c. Panel photograph at station location 20+19 on the left rib in the lower lithophysal zone with Small-Scale Fracture data (trace lengths of fractures as 
yellow lines) and panel map data (lithophysal cavities, rims, spots, and lithic clasts) inside the 1x3-m red rectangle. Figure A-18b displays the detailed 
panel map at 21+25. Lithophysal cavities greater than 20 cm in diameter are labeled in cyan, the yellow circle is 20 cm in diameter, and red-painted 
lines (far left) are fractures greater than 1 m in length that were mapped as part of the Detailed Line Survey. 
Figure A1-19. Panel Photographs with Locations of Lithophysal Cavities Greater than 20 cm in Diameter that were Inventoried for Shape and 
Possible Collapse Features (Continued) 

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ANL-MGR-GS-000004 REV 00 A-38 February 2005 
The 1x3-m panel maps and 2x6-m panel photographs document 1444 lithophysae from the upper 
lithophysal, middle nonlithophysal, and lower lithophysal zones in the ECRB Cross-Drift 
(Table A1-5). In the panel photographs, 34 lithophysae are identified only as backfilled. Of 
the 1410 lithophysae that have easily identifiable initial shapes, 76.8 percent have simple shapes, 
8.0 percent have merged shapes, 2.4 percent have cuspate shapes, and 12.8 percent have 
expansion-crack shapes (Table A1-5). During data collection, the effects of damage to these 
shapes were implicitly evaluated and determined to be minimal. The apparent damage 
typically was attributed to plucking of pieces on the edges, which were bounded by very small 
fractures, and were plucked during cutting by the TBM or the (fairly aggressive) washing of the 
walls. What this means is that the walls of the lithophysae away from the plucked segments 
have intact vapor-phase mineral coatings and features such as small expansion cracks. Of the 
lithophysae examined, there are none that are categorized as collapsed. 
Some lithophysae have coatings of calcite along the floor, but the occurrence of rock fragments 
included in and cemented by the calcite coatings, as described by Whelan (2004 
[DIRS 170697]), was not documented in the present study. Some lithophysae have small piles of 
loose rubble on the floors. However, these deposits were inevitably determined to be residual 
piles of muck from the TBM that had not been washed out because (1) the apparent grain size 
distributions were consistent with the tunnel muck, and (2) fairly delicate features such as 
vapor-phase mineral lining and expansion cracks on the roofs and walls of the lithophysae are 
intact. 
Of the lithophysae inspected, only 7 are transected (or intersected) by fractures, and only 5 are 
transected by shears. In the panel photograph at station 07+40 on the left wall (Figure A1-19), 
two lithophysae are transected by fractures (in the lower left) and two lithophysae are at the 
terminal ends of fractures (upper left and lower right). 
The conclusion of this re-examination of lithophysal cavity shapes in panel maps and panel 
photographs along the ECRB Cross-Drift is that none of the lithophysae depict damage attributed 
to shaking or mechanical degradation of the rock. Even the few lithophysae that (1) are 
transected by fractures, (2) are the terminal end of fractures, or (3) occur along shears, have no 
appreciable effects of damage to the walls of the lithophysae. 
Table A1-5. Initial Shapes of Lithophysae, Backfilled Lithophysae, and Lithophysae that are Transected 
by Fractures or Shears in Panel Maps and Panel Photographs in the ECRB Cross-Drift 
Type of Data Simple Merged Cuspate 
Expansion- 
Crack 
Total 
Initial 
Shapes Backfilled Collapsed 
Fracture 
Transected Sheared 
Panel map 940 89 18 61 1108 0 0 0 3 
Panel 
photograph 
143 24 16 119 302 34 0 7 2 
Total Number 1083 113 34 180 1410 34 0 7 5 
Source: PGV Lithop Shapes ECRB.xls (Appendix D) 
A1.1.3 Interaction of Fractures and Lithophysae as Large Strain Indicators 
Failure of lithophysal rocks in laboratory experiments indicates that fractures typically develop 
through the rock material and many of the fractures connect lithophysae to form 
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ANL-MGR-GS-000004 REV 00 A-39 February 2005 
inter-lithophysae fracture networks. Modeling of rock mechanics with the Particle Flow Code 
(PFC) computer program enables detailed analyses of the failure mechanisms and the 
development of inter-lithophysae fractures. The 2-dimensional PFC (PFC2D) rock mechanics 
model for lithophysal rocks consists of a 1x1-m sized sample that has been calibrated to 
laboratory results (see Section 6.4 and Appendix B). PFC2D model results indicate that the 
inter-lithophysae fractures develop in samples where the lithophysae are depicted as circles, 
triangles, stars, or realistic shapes copied from stencils derived from the panel maps 
(BSC 2003 [DIRS 166660], Attachment V-Appendix B). Examples of six stress-strain, PFC 
model results from stencils derived from panel maps at 16+24 (right wall) and 16+41 (left wall) 
are depicted in Figure A1-20a and b. In these PFC model results, the blue lines are microfractures 
formed prior to failure at peak strength and red lines are micro-fractures formed postfailure 
at peak strength. 
The criteria for determining how and when micro-fractures form relative to increasing levels of 
shear strain are described in detail in Section 6.4 and Appendix B; however, what is critical from 
the field point of view is if micro-fractures are integrated into systematic fractures that can be 
identified in the field. The integration of micro-fractures into observable inter-lithophysae 
fractures and patterns is the key field-based relation of lithophysae and fractures that is used to 
evaluate whether or not the rocks have ever been exposed to strains large enough to result in 
failure. This geologically-based observation is comparable to the three damage state definitions 
discussed in the context of the laboratory tests and rock mechanics modeling: volumetric strain 
reversal, onset of systematic fracturing, and peak stress (see Section 6.4 and Appendix B). 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-40 February 2005 
Sources: DTN: GS021008314224.002 [DIRS 161910]; BSC (2003 [DIRS 166660], Attachment V- Appendix B, Figure B-4). 
NOTE: Upper part of figure shows stress-strain model results (BSC 2004 [DIRS 172334]) using the software code PFC2D. Blue lines are micro-fractures 
formed prior to failure at peak strength and red lines are micro-fractures formed post-failure at peak strength. Embedded lithophysae are derived from 
stencils taken from the panel map below. The lower part of the figure is the panel map at 16+24 on the right wall with 300 photographically interpreted 
fractures (yellow lines). 
Figure A1-20a. Comparison of Modeled Fracture Development in Lithophysal Rock Samples that are Deformed to Failure to Observed Fractures 
in the Enhanced Characterization of the Repository Block Cross-Drift 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-41 February 2005 
Sources: DTN: GS021008314224.002 [DIRS 161910]; BSC (2003 [DIRS 166660], Attachment V-Appendix B, Figure B-5). 
NOTE: Upper part of figure shows stress-strain model results (BSC 2004 [DIRS 172334]) using the software code PFC2D. Blue lines are micro-fractures 
formed prior to failure at peak strength and red lines are micro-fractures formed post-failure at peak strength. Embedded lithophysae are derived from 
stencils taken from the panel map below. The lower part of the figure is the panel map at 16+41 on the left wall. 
Figure A1-20b. Comparison of Modeled Fracture Development in Lithophysal Rock Samples that are Deformed to Failure to Observed Fractures 
in the Enhanced Characterization of the Repository Block Cross-Drift (Continued) 
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ANL-MGR-GS-000004 REV 00 A-42 February 2005 
To better document the relations of fractures and lithophysae in the upper lithophysal, middle 
nonlithophysal, and lower lithophysal zones, photographs of the tunnel walls in the ECRB 
Cross-Drift have been examined. In the lower lithophysal zone, photographs of five of the 
Small-Scale Fracture study locations have the traces of the recorded fractures marked on the wall 
(in black) (photographs SSF1805L, SSF1886L, SSF1920L, SSF2071L, and SSF2125L), and for 
one location, the traces have been overlain on the photograph to make them more visible 
(photograph SSF2019L) (Figure A1-19c, Section A4, GS040408314224.003 [DIRS 170312]). 
None of the panel maps or panel photographs have explicitly been used to create 2-dimensional 
fracture maps in the field. One panel map at 16+24 on the right wall (16+24R) in the lower 
lithophysal zone was used to develop a photographically interpreted fracture map 
(Figure A1-20a). In this map, the edges of lithophysae cavities, rims and spots (red, green, and 
cyan lines, respectively) were mapped; however, expansion cracks and other fractures inside the 
lithophysae were not mapped. Some of the lithophysae have moderate-to well-developed 
circum-lithophysal cavity fractures such as the almost 50-cm diameter expansion-crack 
lithophysae in the center of the panel map 16+24R (Figure A1-20a). 
There are several lithophysae-fracture relations, summarized below, for the 167 fractures 
depicted in the Small-Scale Fracture data at 20+19L (Figure A1-19c, PGV SSF DLS Frac-Fill.xls 
in Appendix D) and the 300 fractures depicted on the panel map at 16+24R (Figure A1-20a). 
Although detailed fractures have not mapped, many of these relations are also in other panel 
maps and panel photographs (see Section A3 and A4). 
1. Most fractures have trace lengths less than 30 cm long, and only a few are greater than 
50 cm long. 
2. Most fractures are steeply dipping; however, some that appear to be more shallowly 
dipping might in fact be steeply dipping but with an apparent shallow dip in the plane 
of the tunnel cut. 
3. Many fractures have developed in the matrix-groundmass and appear to have formed 
irrespective of the occurrence of a lithophysae nearby. 
4. Some fractures intersect or truncate into lithophysae, but few appear to transect 
lithophysae. 
5. Several fractures are "circum-lithophysal" fractures that formed around or parallel to 
the margins of lithophysae. 
Photographs used for this re-examination of the relations of lithophysae and fractures represent 
only about 2 percent of the total exposed area of the tunnel walls. However, the locations of the 
photographs and subsequent studies were identified as being representative of the rocks at 
various positions along the ECRB Cross-Drift. 
The conclusion of this re-evaluation of the photographs is that most of the relations of 
lithophysae and fractures in the photographs are consistent with (1) localized in situ fracturing of 
the matrix-groundmass during cooling of the rock mass, or (2) minor amounts of extension of the 
rock mass, probably during structural tilting of the mountain. Some fractures appear to form the 
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ANL-MGR-GS-000004 REV 00 A-43 February 2005 
type of observable inter-lithophysae fractures and patterns that are predicted from the PFC 
models, but these are relatively few in number and are not pervasive. 
A1.2 SUMMARY OF THE GEOLOGIC CONSTRAINTS ON THE TIMING OF 
LITHOPHYSAE AND FRACTURE FORMATION 
The features in a rock represent the major processes that have occurred through its geologic 
history; therefore, the features are used to reconstruct the sequential development of the 
rock-forming processes. This sequential development of features are placed in a temporal (or 
petrogenetic) framework that constrains how and when subsequent processes occurred. 
Furthermore, this petrogenetic framework is used to evaluate whether or not the rocks have ever 
experienced stresses great enough to result in mechanical failure of the rocks. Beyond the initial 
cooling-related sources of stress and strain, one of the prime sources of stress and strain to be 
considered are those associated with paleoseismic events. 
The lithostratigraphic units in the Topopah Spring Tuff comprising the repository host horizon 
consist of densely welded, crystallized, and lithophysal or nonlithophysal rocks. During the 
welding process, the redistribution of the vapor phase resulted in development of lithophysae and 
transfer of the vapor phase along fractures. During and shortly after the development of 
lithophysal cavities and early-formed (Type 1 and Type 1s) fractures, the glass crystallized in the 
presence of the vapor (but not from the vapor) along the margins of lithophysal cavities and 
fractures to form light gray to pinkish gray rims. Even some of the matrix-groundmass 
surrounding the lithophysae and some fractures crystallized to form grayish red purple borders 
and reddish gray matrix-groundmass, and these features are consistent with crystallization of the 
matrix-groundmass in the presence of vapor. In the areas farthest from lithophysae and 
early-formed fractures, the matrix-groundmass is typically reddish brown, and it is interpreted as 
having crystallized in the absence of vapor. Fractures that formed late in the cooling history of 
the deposit do not have rims, formed when the rock was mostly (if not entirely) crystallized, and 
these fractures are indicative of Type 2 and Type 2s fractures. Vapor-phase mineral coatings 
typically are on cooling fractures, but they are not necessarily on all cooling fractures because 
the fracture could have formed after most of the vapor phase had been removed from the area, or 
the three-dimensional network of fractures simply did not penetrate a region of abundant vapor 
phase material. Lack of distinctive features such as rims or vapor-phase mineral coatings means 
that some Type 2 fractures might not be identified as being cooling fractures and might be 
identified as Type 3 fractures (those that formed after the rock had cooled to the ambient 
temperatures of a rock at the paleogeomorphic surface). To put this another way, some of the 
indeterminate fractures (those that do not have distinctive cooling related features such as 
rims or vapor-phase mineral coatings) can be consistent with being Type 2 cooling fractures. 
Although not examined in this evaluation, other properties of fractures such as orientation, 
planarity, roughness, and trace length might be used to help categorize indeterminate fractures 
as being Type 2 cooling fractures or Type 3 fractures. 
Data from the fractures in slabs of core and DLS in the ECRB Cross-Drift were collected for 
different reasons and represent different scales of sample size and resolution; however, they form 
a consistent set of relations (1) in the petrogenetic formation of the cooling features of fractures, 
(2) where about 70 percent of fractures are related to cooling and 30 percent are indeterminate 
(but might be late-stage cooling related), and (3) where the vast majority of fractures have no 
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ANL-MGR-GS-000004 REV 00 A-44 February 2005 
evidence of shear or mechanical degradation. In the DLS data from the ECRB Cross-Drift, the 
ratio of cooling and indeterminate features is not exactly the same in fractures, shears, and 
broken or crushed rock or sand material filled discontinuities; however, the overall proportions 
of cooling and indeterminate features in these different discontinuities are consistent with the 
formation of an intricate, early formed, fracture network. 
Lithophysal cavities developed very early in the formation of the rock (probably in the first few 
years after deposition), and are suspected as being sensitive indicators of applied strains. Of the 
1410 lithophysae described in the panel maps and inventoried in the panel photographs, all the 
lithophysae have shapes that are consistent with the initial formation of the lithophysae during 
welding of the ignimbrite. None of the lithophysae show damage or collapse that could be the 
result of extreme earthquake ground motions. Of the 1444 lithophysae inspected, only 7 are 
transected (or intersected) by fractures greater than 1 m in trace length (the fractures were 
mapped during collection of DLS data), and only 5 are transected by shears. Although a few 
lithophysae (1) are transected by fractures, (2) are the terminal end of fractures, or (3) occur 
along shears, none have appreciable effects of damage to the walls of the lithophysae. 
On the basis of PFC2D numerical simulations of rock mechanic properties, one of the most 
diagnostic relations of lithophysal rocks that have been subjected to significant shear strains is 
the development of a pervasive network of inter-lithophysal fractures and patterns (Section 6.4 
and Appendix B). With increasing shear strain, micro-fractures integrate and form observable 
inter-lithophysal fractures and patterns. These observable inter-lithophysal fractures and patterns 
are comparable to the volumetric strain reversal, onset of systematic fracturing, and peak stress 
damage state definitions discussed in Section 6.4 and Appendix B. The 38 photographs of tunnel 
walls document textural and structural relations in rocks that contain lithophysae from the upper 
lithophysal and lower lithophysal zones (including two photographs from the 
lithophysae-bearing subzone of the middle nonlithophysal zone). Most of the relations of 
lithophysae and fractures in the photographs are consistent with (1) localized in situ fracturing of 
the matrix-groundmass during cooling of the rock mass, or (2) minor amounts of extension of the 
rock mass, probably during structural tilting of the mountain. 
The four studies described in this Appendix document lithostratigraphic relations of lithophysae 
and fractures in densely welded and crystallized rocks in the 12.8-million-year old Topopah 
Spring Tuff, and by their occurrence (or lack thereof) help establish limits on the maximum 
strain the rocks have experienced since the time of deposition (for discussions on the strains, see 
section 6.4 and Appendix B). Because seismically induced stresses and ground motion affect 
large areas (and volumes) of the rock mass, the evaluation of several different lithostratigraphic 
units with spatially distributed samples more appropriately addresses probable 
geologically-observable ground motions than do studies in and adjacent to faults. Although the 
samples used in these four studies are limited in size and scale relative to the entire rock mass, 
one of the underlying strengths of these studies is that samples and study locations are spatially 
and stratigraphically distributed through the rock mass. There are localized examples of 
fractures that (1) might have resulted from minor amounts of shear and (2) are consistent with 
geometric relations indicative of the observable inter-lithophysal fractures and patterns. 
However, the vast majority of the results from these four studies indicate the rocks have not 
experienced failure and catastrophic damage of the rock mass of the Topopah Spring Tuff. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-45 February 2005 
A2. SOURCE INFORMATION FOR BOREHOLES 
Table A2.1. Table of Borehole Identifiers and Citations from the Sample Management and Drilling 
Department Geologic Logs Used for Diameters of Core and Station Locations of ThermK 
and GETC Boreholes 
Borehole Accession Number Reference [DIRS] 
USW NRG-6 DRC.19960509.0104 YMP (1993 [172106]) 
USW UZ-14 DRC.19960702.0263 YMP (1995 [172113]) 
ECRB ThermK-001 MOL.20010614.0098 YMP (2001 [172115]) 
ECRB ThermK-002 .0135 YMP (2001 [172116]) 
ECRB ThermK-003 .0103 YMP (2001 [172117]) 
ECRB ThermK-004 .0108 YMP (2001 [172118]) 
ECRB ThermK-005 .0113 YMP (2001 [172119}) 
ECRB ThermK-006 MOL.20010913.0334 YMP (2001 [172121]) 
ECRB ThermK-007 .0339 YMP (2001 [172122]) 
ECRB ThermK-008 .0344 YMP (2001 [172124]) 
ECRB ThermK-009 .0349 YMP (2001 [172131}) 
ECRB ThermK-010 .0354 YMP (2001 [172132]) 
ECRB ThermK-011 .0359 YMP (2001 [172136]) 
ESF ThermK-012 MOL.20030709.0313 YMP (2003 [172138]) 
ESF ThermK-013 .0317 YMP (2003 [172141]) 
ESF ThermK-014 .0321 YMP (2003 [172143]) 
ESF ThermK-015 .0325 YMP (2003 [172145]) 
ESF ThermK-016 .0329 YMP (2003 [172146]) 
ESF ThermK-017 .0334 YMP (2003 [172149]) 
ESF ThermK-018 .0338 YMP (2003 [172150]) 
ESF ThermK-019 .0343 YMP (2003 [172151]) 
ESF-GTEC-CS6500-01 MOL.20020703.0126 YMP (2002 [172152}) 
ESF-GTEC-CS6500-01A .0130 YMP (2002 [172154}) 
ESF-GTEC-CS6500-02 .0134 YMP (2002 [172155]) 
ESF-GTEC-CS6500-04 .0142 YMP (2002 [172156]) 
ESF-GTEC-CS6500-04A .0146 YMP (2002 [172157]) 
ESF-GTEC-CS6500-05A .0154 YMP (2002 [172158]) 
ESF-GTEC-CS6500-05B .0158 YMP (2002 [172180]) 
ESF-GTEC-CS6500-06 .0162 YMP (2002 [172181]) 
ECRB-GTEC-CS1600-08 MOL.20020710.0211 YMP (2002 [172183]) 
ECRB-GTEC-CS1922-01 MOL.20021104.0116 YMP (2002 [172184]) 
ECRB-GTEC-CS1928-01 .0132 YMP (2002 [172185]) 
ECRB-GTEC-CS1928-03 .0140 YMP (2002 [172186]) 
ECRB-GTEC-CS1995-01 .0145 YMP (2002 [172187]) 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-46 February 2005 
A3. PANEL MAPS IN THE LOWER LITHOPHYSAL ZONE OF THE TOPOPAH 
SPRING TUFF EXPOSED IN THE ECRB CROSS-DRIFT FROM STATIONS 
14+44 TO 23+26. FILES ARE FROM DTN: GS021008314224.002 
The 18 Panel Maps that were completed in 2003 (DTN: GS021008314224.002 [DIRS 161910]) 
are reproduced in this section (Table A3-1). These maps were designed to be plotted on 
11x17-inch paper (or larger) or viewed electronically such that the zoom function can be used 
to see many of the details of the maps and features in the rocks. The Zoom function in 
Microsoft Word will also enable focusing in on specific features. So, although some of the text 
might be fairly small in the following paper copy reproductions, most of it can be identified in 
the electronic copy, otherwise please refer to the original data package. 
Table A3-1. Locations of Panel Maps from the Lower Lithophysal Zone (Tptpll) in the ECRB Cross-Drift 
and the File Names of the Images (DTN: GS021008314224.002 [DIRS 161910]) 
Study Image Name Station Wall Lithostratigraphic Unit 
Panel map, lithophysal study PM1493R 14+93 Right Tptpll 
Panel map, lithophysal study PM1551L 15+51 Left Tptpll 
Panel map, lithophysal study PM1610R 16+10 Right Tptpll 
Panel map, lithophysal study PM1624R 16+24 Right Tptpll 
Panel map, lithophysal study PM1641L 16+41 Left Tptpll 
Panel map, lithophysal study PM1641R 16+41 Right Tptpll 
Panel map, lithophysal study PM1656L 16+56 Left Tptpll 
Panel map, lithophysal study PM1726L 17+26 Left Tptpll 
Panel map, lithophysal study PM1768L 17+68 Left Tptpll 
Panel map, lithophysal study PM1768R 17+68 Right Tptpll 
Panel map, lithophysal study PM1805L 18+05 Left Tptpll 
Panel map, lithophysal study PM1886L 18+86 Left Tptpll 
Panel map, lithophysal study PM1919L 19+19 Left Tptpll 
Panel map, lithophysal study PM2018L 20+18 Left Tptpll 
Panel map, lithophysal study PM2069L 20+69 Left Tptpll 
Panel map, lithophysal study PM2124L 21+24 Left Tptpll 
Panel map, lithophysal study PM2232L 22+32 Left Tptpll 
Panel map, lithophysal study PM2294L 22+94 Left Tptpll 
Panel maps contain several items. 
1 Metric scale is on the left. 
2 General information for the panel map. 
3 The photograph is a composite of 3 digital images that were taken with low-angle illumination. 
4 Red painted lines on the left walls are fractures that were mapped in the total ECRB DLS traverses. 
5 Red rectangles are the area of Panel Maps. 
6 Lithophysae (including cavities and associated rims) are labeled with red L, spots are cyan S, and lithic clasts 
are dark yellow C. 
7 Lithophysal cavities are outlined with red, rims are green, spots are blue, and lithic clasts are dark yellow. 
Photographs of some panels were taken prior to the digging out of lithophysae that were back-filled by muck from 
the Tunnel Boring Machine. 
8 Abundance and cumulative frequency of the areas (mm2) of lithophysal cavities, rims, and spots are plotted with 
equivalent areas of circles with various diameters. 
9 The table in the upper right summarizes the abundance (percent) of each component, the 
porosity of each component, contribution to the total porosity of the components, and the total 
porosity of the rock. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-47 February 2005 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-1. Panel Photograph at Station 14+93 on Right Wall 
ANL-MGR-GS-000004 REV 00 A-48 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-2. Panel Photograph at Station 15+51 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-49 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-3. Panel Photograph at Station 16+10 on Right Wall 
ANL-MGR-GS-000004 REV 00 A-50 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-4. Panel Photograph at Station 16+24 on Right Wall 
ANL-MGR-GS-000004 REV 00 A-51 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-5. Panel Photograph at Station 16+41 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-52 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-6. Panel Photograph at Station 16+41 on Right Wall 
ANL-MGR-GS-000004 REV 00 A-53 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-7. Panel Photograph at Station 16+56 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-54 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-8. Panel Photograph at Station 17+26 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-55 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-9. Panel Photograph at Station 17+68 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-56 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-10. Panel Photograph at Station 17+68 on Right Wall 
ANL-MGR-GS-000004 REV 00 A-57 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-11. Panel Photograph at Station 18+05 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-58 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-12. Panel Photograph at Station 18+86 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-59 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-13. Panel Photograph at Station 19+19 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-60 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-14. Panel Photograph at Station 20+18 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-61 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-15. Panel Photograph at Station 20+69 on Left Wall 

ANL-MGR-GS-000004 REV 00 A-62 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-16. Panel Photograph at Station 21+24 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-63 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-17. Panel Photograph at Station 22+32 on Left Wall 
ANL-MGR-GS-000004 REV 00 A-64 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
Source: DTN: GS021008314224.002 [DIRS 161910]. 
Figure A3-18. Panel Photograph at Station 22+94 on Left Wall
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-65 February 2005 
A4. PANEL PHOTOGRAPHS IN THE UPPER LITHOPHYSAL, MIDDLE 
NONLITHOPHYSAL, AND LOWER LITHOPHYSAL ZONES OF THE 
TOPOPAH SPRING TUFF EXPOSED IN THE ECRB CROSS-DRIFT FROM 
STATIONS 06+50 TO 21+25 
The 20 Panel Photographs and photographs of the Small-Scale Fracture locations are reproduced 
in this section (Table A4-1). These maps were designed to be plotted on 11x17-inch paper (or 
larger) or viewed electronically such that the zoom function can be used to see many of the 
details of the maps and features in the rocks. The Zoom function in Microsoft Word will 
also enable focusing in on specific features. So, although some of the text might be fairly small 
in the following paper copy reproductions, most of it can be identified in the electronic copy, 
otherwise please refer to the original data package. 
Table A4-1. Locations of Photographs for the Small-Scale Fracture and Panel Photograph Studies in the 
ECRB Cross-Drift and File Names of the Images (DTN: MO0402GSC04031.000 
[DIRS 172231]) 
Study 
Additional 
Data on Images Image Name Station Wall 
Lithostratigraphic 
Zone 
Small Scale Fracture study L-20cm PP0660L 06+60 Left Tptpul 
Panel photograph study L-20cm PP0660R 06+60 Right Tptpul 
Panel photograph study L-20cm PP0745L 07+45 Left Tptpul 
Panel photograph study L-20cm PP0745R 07+45 Right Tptpul 
Panel photograph study PP0815L 08+15 Left Tptpul 
Panel photograph study L-20cm PP0816R 08+16 Right Tptpul 
Panel photograph study PP0910L 09+10 Left Tptpul 
Panel photograph study L-20cm PP0910R 09+10 Right Tptpul 
Panel photograph study PP0935L 09+35 Left Tptpul 
Panel photograph study L-20cm PP0935R 09+35 Right Tptpul 
Small Scale Fracture study PP1035L 10+35 Left Tptpmn 
Panel photograph study L-20cm PP1035R 10+35 Right Tptpmn 
Panel photograph study PP1220L 12+20 Left Tptpmn 
Panel photograph study L-20cm PP1218R 12+18 Right Tptpmn 
Small Scale Fracture study L-20cm, SSF SSF1805L 18+05 Left Tptpll 
Small Scale Fracture study L-20cm, SSF SSF1886L 18+86 Left Tptpll 
Small Scale Fracture study SSF SSF1920L 19+20 Left Tptpll 
Small Scale Fracture study SSF SSF2019L 20+19 Left Tptpll 
Small Scale Fracture study SSF SSF2071L 20+71 Left Tptpll 
Small Scale Fracture study SSF SSF2125L 21+25 Left Tptpll 
NOTE: Objects that occur on many of the photographs include the following: 
1 Metric scale is on the left. 
2 Yellow circle is 20 cm in diameter. 
3 Red painted lines on the left walls are fractures that were mapped in the total ECRB DLS traverses. 
4 Red rectangles are the area of Panel Maps. 
5 Cyan labels such as PL14 are photographically interpreted lithophysae that are larger than 20 cm in 
diameter with the shapes documented in the workbook PGV Lithop Shapes ECRB.xls. 
6 On the SSF photographs, many of the mapped fractures are labeled in black lines and text where they 
intersect the tape. 
7 Station location labels in the upper-left corners of the photographs were inserted by the photographer 
and are approximate locations determined in the field. Official surveyed station locations on pins or 
targets are listed in the table. 
ANL-MGR-GS-000004 REV 00 A-66 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
a 
b 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-1a. Panel Photograph at Station 06+60 on Left Wall and Small-Scale Fracture Traverse Location H15 with Vertical Traverses V37, 
V41, and V42 with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 
Figure A4-1b. Panel Photograph at Station 06+60 on Right Wall with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 
ANL-MGR-GS-000004 REV 00 A-67 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
a 
b 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-2a. Panel Photograph at Station 07+45 on Left Wall and Small-Scale Fracture Traverse Location H15 with Vertical Traverses V37, 
V41, and V42 with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 
Figure A4-2b. Panel Photograph at Station 07+45 on Right Wall with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 
ANL-MGR-GS-000004 REV 00 A-68 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
a 
b 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-3a. Panel Photograph at Station 08+15 on Left Wall with Panel Map 08+15L Location Indicated in Red Box 
Figure A4-3b. Panel Photograph at Station 08+16 on Right Wall with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 
ANL-MGR-GS-000004 REV 00 A-69 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
a 
b 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-4a. Panel Photograph at Station 09+10 on Left Wall with Panel Map 09+10L Location Indicated in Red Box 
Figure A4-4b. Panel Photograph at Station 09+10 on Right Wall with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 
ANL-MGR-GS-000004 REV 00 A-70 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
a 
b 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-5a. Panel Photograph at Station 09+35 on Left Wall and Small-Scale Fracture Traverse Location H16 with Vertical Traverses V38, 
V39, and V40 with Panel Map 09+35L Location Indicated in Red Box 
Figure A4-5b. Panel Photograph at Station 09+35 on Right Wall with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 
ANL-MGR-GS-000004 REV 00 A-71 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
a 
b 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-6a. Panel Photograph at Station 10+35 on Left Wall with Panel Map 10+35L Location Indicated in Red Box 
Figure A4-6b. Panel Photograph at Station 10+35 on Right Wall with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 

ANL-MGR-GS-000004 REV 00 A-72 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
a 
b 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-7a. Panel Photograph at Station 12+20 on Left Wall with Panel Map 12+20L Location Indicated in Red Box 
Figure A4-7b. Panel Photograph at Station 12+18 on Right Wall with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape 
ANL-MGR-GS-000004 REV 00 A-73 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
8 
9 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-8. Panel Photograph at Station 18+05 on Left Wall and Small-Scale Fracture Traverse Location H7 with Vertical Traverses V19, V20, 
and V21 with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape and Panel Map 18+05L Location Indicated in Red 
Box (See Section A3) 
Figure A4-9. Panel Photograph at Station 18+86 on Left Wall and Small-Scale Fracture Traverse Location H8 and H9 with Vertical Traverses 
V22, V23, and V24 with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape and Panel Map 18+86L Location 
Indicated in Red Box (See Section A3) 
ANL-MGR-GS-000004 REV 00 A-74 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
a 
b 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-10a. Panel Photograph at Station 19+20 on Left Wall and Small-Scale Fracture Traverse Location H14 with Vertical Traverses V34, 
V35, and V36 with Panel Map 19+19L Location Indicated in Red Box (See Section A3) 
Figure A4-10b. Panel Photograph at Station 20+19 on Left Wall and Small-Scale Fracture Traverse Location H10 and H11 with Vertical 
Traverses V25, V26, and V27 with Lithophysae Larger Than 20 cm in Diameter Inventoried for Shape and Panel Map 20+18L 
Location Indicated in Red Box (See Section A3) 
ANL-MGR-GS-000004 REV 00 A-75 February 2005 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
11 
12 
NOTE: Survey station locations from DTN: MO0402GSC04031.000 [DIRS 172231]; labeled lithophysae in PGV Lithop Shapes ECRB.xls in Appendix D. 
Figure A4-11. Panel Photograph at Station 20+71 on Left Wall and Small-Scale Fracture Traverse Location H13 with Vertical Traverses V33, 
V28, and V29 with Panel Map 20+69L Location Indicated in Red Box (See Section A3) 
Figure A4-12. Panel Photograph at Station 21+25 on Left Wall and Small-Scale Fracture Traverse Location H12 with Vertical Traverses V30, 
V31, and V32 with Panel Map 21+24L Location Indicated in Red Box (See Section A3) 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 A-76 February 2005 
INTENTIONALLY LEFT BLANK 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 February 2005 
APPENDIX B 
STRAIN LEVELS RELATED TO DAMAGE IN TOPOPAH SPRING TUFF 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 February 2005 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 B-1 February 2005 
B1. BACKGROUND 
A credible way to provide limits to the maximum peak ground velocity (PGV) of the synthetic 
time histories used as input to seismic analyses for the Yucca Mountain Project is to estimate the 
maximum PGV that could have been experienced at the site in the geological past. To make this 
estimate, at least two pieces of evidence are necessary: 
1. Observations of strain-induced fractures around lithophysae (or lack of such fractures); 
and 
2. Data on the mean strain necessary to initiate fracturing around lithophysae. 
Evidence in the first category is available from observations in the Exploratory Study Facility 
(ESF) and Enhanced Characterization of Repository Block (ECRB) Cross-Drift, which indicate 
that the majority of the fractures in the lithophysal and nonlithophysal units are induced 
thermally (see Appendix A). 
To supply evidence in the second category, and to evaluate the upper bound to the seismically 
induced strain experienced by the Topopah Spring Tuff since it has cooled, the shear-strain 
increments required to cause fracturing of the lithophysal rock mass were calculated based on 
results of previously performed laboratory compression tests (for units in which the proper test 
results are available) and results of PFC2D (BSC 2004 [DIRS 169930]) and UDEC (BSC 2002 
[DIRS 161949]) numerical micro-mechanical models. 
The results of the laboratory uniaxial compression tests were used to estimate the shear-strain 
increment limit in a lithophysal rock mass. The numerical results of PFC2D and UDEC, based 
on and calibrated to results of laboratory tests, were used to extrapolate experimental results to 
wider ranges of lithophysal porosity and different loading conditions that could not be tested in 
the laboratory (e.g., laboratory tests were conducted for unconfined conditions only). The 
numerical models also were used to establish the relation between different states of damage 
evolution and strain. Only the strain at peak stress could be determined from the laboratory 
results. The results of existing simulations performed in a previous study are re-analyzed. The 
previous study consisted of modeling mechanical behavior of lithophysal tuff (BSC 2004 
[DIRS 172334]). In this study, characteristic fractures were seen to develop around and between 
lithophysae. The objective of the study was not the correlation of damage with strain per se, but 
it is possible to re-interpret these results to generate statistical data on the amount of damage 
(fracturing around lithophysae) related to strain level. Thus, certain features of the simulations 
(such as levels of confining stress) are not optimal for the present purpose. 
The methodology of calculation and shear-strain increments corresponding to different damage 
states in a lithophysal rock mass is discussed in Section B2. 
B2. STRAIN LIMITS IN LITHOPHYSAL TUFF 
B2.1 DAMAGE STATES IN LITHOPHYSAL TUFF 
First, a decision must be made about the damage state (limiting state) at which fracturing would 
be observable in the field. Clearly, the state at which the first microfractures appear in the intact 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 B-2 February 2005 
rock matrix would be an underestimate of the threshold shear strain (even though it is recorded in 
the numerical test), because a few unconnected microfractures would be unnoticed in the field 
and in the laboratory experiment. It is chosen to record results for three states when possible: 
(a) the state at which the volumetric strain rate reverses (from compaction to expansion); (b) the 
onset of systematic fracturing (OSF); and (c) the state at which the peak stress occurs (i.e., the 
strength of the sample). 
Figure B-1 illustrates typical fracturing predicted by the calibrated PFC2D model occurring in a 
simulated (synthetic) lithophysal rock sample that has been stressed to failure under uniaxial 
compression. In this simplest of modeling approaches, the lithophysal voids are represented as 
circular holes distributed throughout the sample. The rock matrix in this model is composed of 
several thousand circular particles (too small to be seen at this scale) which are bonded with 
tensile and shear bonds at their contacts. Fractures, which occur due to breakage of these contact 
bonds when the sample is stressed, can be seen as red and blue lines within the sample.. At the 
peak stress point, there usually is considerable damage (e.g., blue fractures in Figure B-1). 
Analyses of compression of synthetic rock samples show that stress-induced fractures would be 
expected to interconnect the lithophysae, which act as locations of stress concentration within the 
mass. This form of predicted fracture development  ubiquitous, long inter-lithophysal 
fracturing  would allow such fractures to be distinguishedin underground observationsfrom 
typical cooling fractures. 
The strain state at the peak stress is certainly an upper bound to the threshold strain representing 
the state for which the fractures connecting lithophysae would be distinguishable in the geologic 
panel maps of the ESF and the ECRB Cross-Drift. The state at volumetric strain reversal is 
associated with significant damage, as the sample ceases to behave as an elastic continuum. 
Structural changes, due to fractures, are the reason for volumetric expansion. The strain at 
volumetric strain reversal is less than the strain at the peak stress. The strain at the peak stress is 
determined from the data collected during the laboratory test. The information collected during 
the laboratory test is insufficient to determine strain at the volumetric strain reversal or other 
damage states except at the peak stress. 
One of the advantages of numerical tests on synthetic models of rock is the ability to monitor 
evolution of damage much more precisely and at finer detail than is possible in the laboratory. 
Numerical models allow determination of the OSF by direct monitoring of formation and 
propagation of macrofractures by coalescence of microfractures.1 Consequently, it is not 
necessary to use macroscopic measures of stress and strain in the sample to interpret the damage 
state. Instead, the fractures (their number, length and connectivity to the lithophysae) are 
monitored directly during the test. If OSF is determined directly, it is also possible to assess the 
level of conservatism in the strain limits determined from the strains at the volumetric strain 
1 In PFC2D, microfractures are the result of bond breakage between two particles. In actual rock, this corresponds 
to a fracture on the scale of the internal structure of the material (i.e., grain size to a bit larger, millimeter to 
centimeter). Macrofractures develop through the coalescence of microfractures due to stress concentrations and 
interactions. Macrofractures have a dimension comparable in scale to the characteristic dimension of the problem 
that is analyzed (e.g., scale of lithophysae). In the determination of the OSF for PFC2D calculations, 
macrofractures are assessed on the basis of criteria related to the orientation and distance between microfractures. 

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ANL-MGR-GS-000004 REV 00 B-3 February 2005 
reversal and at the peak stress. An algorithm for monitoring the evolution of microfractures has 
been developed and used in PFC2D simulations of uniaxial compressive tests on the lithophysal 
rock mass. 
Source: BSC (2003 [DIRS 166660], Attachment VIII, PFC2D Inputs & Outputs CD #9, sC1_mKb14_tD00- 
bw3.sav); Damjanac et al. (2004 [DIRS 172060], Figure 1). 
NOTE: Blue and red lines are stress-induced fractures developed during a simulated uniaxial compression test. 
The arrows indicate the direction of applied uniaxial stress. Blue lines indicate fractures that developed 
prior to reaching the peak stress; red lines indicate fractures that developed after the peak stress was 
reached. Fractures located in the middle of a circular void represent particles that have broken off from 
the edge of the void. The modeling was carried out using the software code PFC2D (BSC 2004 
[DIRS 169930]). 
Figure B-1. Fractures Developed during Modeled Deformation of a 1-Meter by 1-Meter Synthetic 
Lithophysal Sample 
The microfractures and macrofractures identified during a simulation of a sample with 
lithophysal geometry generated based on the geologic panel maps (BSC 2003 [DIRS 166660], 
Section 9.1, Attachment V) are shown in Figure B-2 on the left and right sides, respectively. The 
algorithm keeps track of fracture score, which is a weighted total length of macrofractures. If 
a macrofracture is not connected to any lithophysae the weight is 0; the macrofracture does not 
contribute to the fracture score. If a macrofracture is connected to a single lithophysae the 
weight is 1. However, if a macrofracture connects 2 lithophysae the weight is 2.i.e., the length 
of the fracture is counted in the score twice. Knowing that the edge length of the sample is 
1 m, it seems reasonable that the OSF would correspond to the fracture score of 0.1 m, because 
this length of connected macrofracture is observable in the field. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 B-4 February 2005 
Source: Damjanac et al. (2004 [DIRS 172060], Figure 2). 
NOTE: For the lithophysae, the colored particles represent their boundaries. Left side: Microfractures. Blue 
signifies shear microfractures and red signifies tensile microfractures. Right side: Macrofractures. Different 
colors are arbitrarily assigned to different macrofractures. 
Figure B-2. Microfractures and Macrofractures Identified in a PFC2D Sample 
The evolution of 3 variables (axial stress, volumetric strain and fracture score) as functions of 
axial strain for the sample in Figure B-2 is shown in Figure B-3. The axial strains at peak stress 
and at the point of volumetric strain reversal are indicated in the figure and correlated to the 
fracture score. At the point of reversal of volumetric strain (axial strain of 0.225%) the fracture 
score is approximately 0.2 m; at peak stress (axial strain of 0.235%) the fracture score is 
approximately 0.3 m. The first significant fracturing (fracture score of 0.075 m) occurs at axial 
strain of 0.175%. The results of four other cases simulated using the algorithm for detection of 
OSF exhibit similar relations. In all cases, significant fracturing (i.e., fracture score on the order 
of 0.1 m) is developed at the peak stresses. The differences between strains at peak stress, at the 
point of volumetric strain reversal and at the OSF (i.e., a state for which fracture score is on the 
order of 0.1 m) are relatively small. These results justify use of the states at peak stress and 
volumetric strain reversal as conservative estimates of the OSF. 
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ANL-MGR-GS-000004 REV 00 B-5 February 2005 
Source: Damjanac et al. 2004 [DIRS 172060], Figure 3. 
Figure B-3. Axial Stress, Volumetric Strain and Fracture Score as Functions of Axial Strain for the 
Sample Shown in Figure B-2 
B2.2 METHODOLOGY FOR CALCULATION OF STRAIN INCREMENT 
The cumulative axial strain at a selected damage state (e.g., peak stress or OSF) cannot be used 
as the strain increment required to cause fracturing of in situ lithophysal rock, because the axial 
strain measured in the laboratory corresponds to a certain uniaxial stress (and corresponding 
strain) path from an initial, unstressed state to the damage state. The rock mass exposed in the 
Yucca Mountain ESF and ECRB Cross-Drift is under an in situ state of stress (strain) with a 
significant deviatoric component. The horizontal principal stresses are between 30% and 60% of 
the vertical principal stress. For dynamic shear strains associated with seismic ground motion to 
cause failure of in situ lithophysal rock, the shear strains would have to exceed the shear-strain 
increment needed to take the rock from the in situ state to the damage state. This is less than the 
shear-strain increment required to take an unstressed sample in the laboratory (or in a numerical 
simulation) to the damage state. Mechanical properties determined from laboratory tests and 
numerical simulations, however, can be used to determine the shear-strain increment required to 
damage a sample initially at the in situ state. 
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In this section, a methodology is discussed for calculating the shear-strain increment that causes 
stress change from an arbitrary initial stress state (e.g., an in situ state) to a state on a surface (or 
line) in stress space that defines a limiting stress state (corresponding to a selected damage state). 
The limiting state is defined by a Mohr-Coulomb condition, a friction angle, f, and a cohesion, c. 
The friction angle in this context characterizes how the limiting state changes as a function of 
confining stress. It is assumed that the friction angle for the limiting state is the same as the 
friction angle related to the yield criterion (or peak stress). In the elastic state, the material is 
characterized by a Youngs Modulus, E , and a Poissons ratio, .. It is assumed that the 
lithophysal rock mass behaves as a linear elastic material until the limiting state is reached. The 
stress path from the initial stress state to the limiting damage state during a strong seismic ground 
motion can be arbitrary. In this analysis, the shear-strain increment is calculated for the stress 
path in which the mean stress does not change. Cyclic shear strain under constant vertical stress, 
which is typically a dominant mode of deformation during a seismic ground motion, results in 
the stress path along which the mean stress is invariant. 
The material initially is in an elastic state with principal stresses 3
E s and 1
E s , respectively (see 
point E in Figure B-4). The mean stress, m s , for this state is defined as 
1 3 
2 m 
s s 
s 
+ 
= (Eq. B-1) 
The material passes from the elastic state (point E in Figure B-4) to the plastic state (point F in 
Figure B-4) while maintaining the same mean stress, m s . In the plastic state (point F), the 
principal stresses are 3
F s and 1
F s . 
Note that in terms of principal stresses, 3 s and 1 s , the Mohr-Coulomb failure criterion can be 
written as (Itasca 2002 [DIRS 160331], FLAC Theory and Background Volume, adapted from 
Section 2.4.2.2) 
1 3 ci K f s s s = + (Eq. B-2) 
where 
1 sin 
1 sin 
K f 
f
f 
+ 
= 
- 
(Eq. B-3) 
and 
2 ci c Kf s = (Eq. B-4) 
sci is the uniaxial compressive strength, which is denoted as qu in workbooks 
Limiting strains-Lab Tests.xls and Limiting strains-Numerical Sims.xls (Appendix D). 
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Source: Damjanac et al. 2004 [DIRS 172060], Figure 4. 
NOTE: On the right side, ts is shear stress, sn is normal stress, and c is cohesion. On the left side, symbols are 
defined in the text. 
Figure B-4. Stress Path Corresponding to Constant Mean Stress Displayed on the Mohr-Coulomb Failure 
Criterion in Terms of Principal Stresses and Normal and Shear Stresses on the Failure Plane 
From a simple geometrical construction, the horizontal coordinate of the intersection point F in 
the left side of the figure is found to be 
3 
2 
1 
F m ci 
K f 
s s 
s 
- 
= 
+ 
(Eq. B-5) 
and the vertical coordinate to be 
1 3 
F F 
ci K f s s s = + (Eq. B-6) 
The increments of major and minor principal stresses when passing from points E to F are 
written as 
1 1 1 
3 3 3 
F E 
F E 
s s s 
s s s 
. = - 
. = - 
(Eq. B-7) 
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ANL-MGR-GS-000004 REV 00 B-8 February 2005 
The relation between the (increment of) strain, 1 e . and 3 e . , and the corresponding (increment 
of) principal stress, 1 s . and 3 s . , is computed from Hookes law, which, for plane strain 
conditions, is (Jaeger and Cook 1979 [DIRS 106219], Section 5.3) 
1 3 
2 
3 
3 1 
2 
1 
) 1 ( 1 
) 1 ( 1 
s 
. . 
s 
. 
e 
s 
. . 
s 
. 
e 
. 
+ 
- . 
- 
= . 
. 
+ 
- . 
- 
= . 
E E 
E E (Eq. B-8) 
Finally, the increment of shear strain (an engineering strain) when the material passes from point 
E to point F in the figure, is written as, 
1 3 . e e . = . - . (Eq. B-9) 
In the following sections the above methodology is used to calculate the shear-strain increment 
associated with moving from an in situ state at the repository waste emplacement level to a 
damage state. Values of Youngs modulus, Poissons ratio, friction angle, yield stress, and peak 
stress are taken from laboratory tests, numerical simulations, or assumed, as appropriate. The 
calculated shear-strain increments are used to establish a probability distribution for the shearstrain 
increment threshold required to damage lithophysal rocks at the waste emplacement level 
(Section 6.4.3). The shear-strain threshold is compared to dynamic shear strains that would be 
produced by extreme ground motion (Section 6.5) to place a bound on the level of ground 
motion that has occurred at Yucca Mountain (Section 6.6). 
B2.3 INTERPRETATION OF LABORATORY RESULTS 
Uniaxial compression tests were conducted on the samples from Topopah Spring Tuff, both 
lithophysal and nonlithophysal. Testing of lithophysal tuff is particularly challenging due to the 
lithophysae. Large diameter samples are required for determination of representative rock mass 
properties. As expected, the mechanical properties of the lithophysal tuff exhibit a strong 
dependence on porosity, which, in turn, can be viewed as a form of sample size dependency. 
Therefore, the results obtained from the tests on the largest samples, the 288-mm diameter cores 
(diameter several times larger than the included lithophysae) taken from the ESF and ECRB 
Cross-Drift, are considered to be the best representation of the mechanical behavior of the 
lithophysal tuff. The uniaxial compression tests provide stress-strain behavior of the lithophysal 
tuff, which includes the axial stress and strain levels associated with peak strength. 
The test results are summarized in Table B-1. The lithophysal porosity, among other 
information, is listed for each sample. (The lithophysal porosity, listed in Table B-1 and used in 
this technical memorandum, is less than the total porosity, which, in addition to lithophysal 
porosity, also includes matrix porosity and the porosities of rims and spots). The primary factor 
controlling the mechanical properties of the lithophysal rocks is lithophysal porosity. 
Distribution of lithophysal porosity as mapped in the ECRB Cross-Drift is shown in Figure B-5. 
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Source: BSC 2004 [DIRS 166107], Figure E-10. 
NOTE: Lithophysal porosity data are from ECRB Cross-Drift station 14+44 to 23+26. 
Figure B-5. Distribution of Lithophysal Porosity in the ECRB Cross-Drift 
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Table B-1. Mechanical Properties of Lithophysal Tuff from 288-mm-Diameter Samples 
Test ID 
Lithostratigraphic Unit 
L:D Ratioa 
Saturation 
Temperature (C) 
Ultimate Strength (MPa) 
Young's Modulus (GPa) 
Poisson's Ratio 
Estimated Lithophysal 
Porosityb 
Source DTNc 
YMPLL49A Tptpll 1.1 : 1 Dry 195 32.2 7.1  11.7 SN0211L0207502.002 
YMPLL43A Tptpll 1.1 : 1 Dry 200 31.1 6.5  20.3 SN0211L0207502.002 
YMPLL23A Tptpll 1.8 : 1 Room Dry 24 28.7 9.2  19.2 SN0211L0207502.002 
YMPLL24A Tptpll 1.8 : 1 Room Dry 24 13.3 5.0  22.2 SN0211L0207502.002 
YMPLL46A Tptpll 1.8 : 1 Room Dry 24 21.7 8.5  28.4 SN0211L0207502.002 
YMPLL87A Tptpll 1.9 : 1 Saturated 24 15.7 5.3  14.5 SN0211L0207502.002 
YMPUL59B Tptpul 1.2 : 1 Dry 190 19.6 7.3  39.4 SN0208L0207502.001 
YMPUL67A Tptpul 1.3 : 1 Dry 190 34.8 9.9  6.2 SN0208L0207502.001 
YMPUL62B Tptpul 1.0 : 1 Dry 200 37.0 13.7  19.3 SN0208L0207502.001 
YMPUL50A Tptpul 1.5 : 1 Room Dry 24 22.1 14.9 0.21 28.5 SN0211L0207502.002 
YMPUL59A Tptpul 2.0 : 1 Room Dry 24 13.5 5.8 0.39 30.3 SN0208L0207502.001 
YMPUL61A Tptpul 1.9 : 1 Room Dry 24 17.7 8.8  23.9 SN0208L0207502.001 
YMPUL62A Tptpul 1.8 : 1 Room Dry 24 25.9 13.7  12.7 SN0208L0207502.001 
YMPUL64A Tptpul 1.7 : 1 Room Dry 24 33.5 20.5  12.8 SN0208L0207502.001 
YMPUL65A Tptpul 2.0 : 1 Room Dry 24 26.2 19.5  11.9 SN0208L0207502.001 
YMPUL66A Tptpul 1.7 : 1 Room Dry 24 16.5 12.4  16.7 SN0208L0207502.001 
YMPUL60A Tptpul 1.8 : 1 Saturated 24 12.7 6.7  18.6 SN0208L0207502.001 
YMPUL63A Tptpul 1.9 : 1 Saturated 24 9.4 5.0 0.24 20.0 SN0208L0207502.001 
YMPUL68A Tptpul 2.1 : 1 Saturated 24 11.6 5.9 0.03 25.8 SN0208L0207502.001 
a Specimen length-to-diameter ratio. 
b Lithophysal property data for tests documented in DTNs SN0208L0207502.001 [DIRS 161871] and 
SN0211L0207502.002 [DIRS 161872] are provided by DTN SN0305L0207502.005 [DIRS 163373]. 
c DTN SN0208L0207502.001 has DIRS number 161871 and DTN SN0211L0207502.002 has DIRS number 161872. 
Source: BSC (2004 [DIRS 172334], Table 6.3-1). 
An example of the stress-strain curve obtained on a sample taken from the lower lithophysal unit 
is shown in Figure B-6. For this sample (test ID YMPLL24A from Table B-1), the reported 
uniaxial unconfined strength is 13.3 MPa, Youngs modulus is 5 GPa, and axial strain at failure 
is 0.4% (Price 2002 [172061], pp. 207-215). Most likely, the initial non-linear portion of the 
curve is not due to non-linear material behavior at low stress levels but, rather, a consequence of 
imperfect contacts between the sample and loading platens. Even if this conjecture is incorrect, 
the initial non-linear strain is inconsequential for calculating shear-strain increment because the 
in situ stress state is larger than the stress level for which non-linear deformation is observed in 
the laboratory experiment. Nominally, the axial strain at the peak stress is 0.4%i.e., point C on 
the curve in Figure B-6. However, from the stress-strain curve, it is clear that the sample is 
already in an active state of failure at point B, or 0.36% of axial strain. In the calculation of the 
shear-strain increment, the material is assumed to behave as linearly elasticperfectly plastic (as 
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ANL-MGR-GS-000004 REV 00 B-11 February 2005 
discussed in Section B2.2). The elastic behavior is controlled by the Youngs modulus, 
determined by the slope of the line between points O and A. The state of failure in the 
elastic-plastic model is at point A, which is, for strain of 0.34%, smaller than strain at point B. 
The difference in the strains between points A (or A) and B is relatively small. Also, 
macro-fractures probably are already visible in the sample at state A. The calculated shear-strain 
increment, from an in situ stress state corresponding to a 250-m overburden to the state A on the 
failure surface, based on this laboratory experiment, is 0.20%, using the correction for in situ 
state described in Section B2.2. The in situ principal stresses for 250 m overburden are vertical, 
1 4.81 E s = MPa, and horizontal, 3 2.41 E s = MPa. The mean stress is an average of 1
E s and 3
E s 
(Eq. B-1). The Youngs modulus, E , (the slope of the linear portion of the loading part of the 
stress-strain curve in Figure B-6) is 5.0 GPa (Test ID YMPLL24A in Table B-1); and the 
uniaxial compressive strength, ci s , is 13.3 MPa (Test ID YMPLL24A in Table B-1). Assuming 
the friction angle, f, to be 30 degrees, stress state (i.e., 1
F s and 3
F s ) at the failure are calculated 
from relations B-5 and B-6. Finally, the shear-strain increment, . . , is calculated from the 
principal strain increments, which are obtained by applying the elastic relation between the stress 
and strain increments (Eq. B-8). 
Pre-existing 
strain at in situ 
stress state 
Source: DTN : SN0211L0207502.002 [DIRS161872], Price (2002 [172061], pp. 207-215). 
Figure B-6. Stress Strain Curve Obtained on a 288-mm Sample (ID YMPLL24A) from the Lower 
Lithophysal Unit, Tested Under Room-Dry Conditions at a Temperature of 24C 
B2.4 SHEAR STRAIN LIMITS ESTIMATED FROM LABORATORY RESULTS 
The shear-strain increments at peak strength were calculated for laboratory results obtained on 
288-mm diameter samples taken from the ESF and ECRB Cross-Drift. The experimental results 
were obtained for unconfined compression conditions only. Calculations were carried out for 
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ANL-MGR-GS-000004 REV 00 B-12 February 2005 
overburden depths of 250 and 400 m representing the range of overburden for the repository 
(Appendix D, Limiting Strains  Lab Tests.xls). An internal angle of friction angle of 30 was 
assumed in the calculation (Section 5, Assumption 2). This assumption results in conservative 
(larger) estimates of the shear strain associated with peak strength and thus larger potential peak 
ground velocities to produce observable yield in situ. The results for the 288-mm diameter 
samples, using an overburden depth of 250 m and divided into two categories based on 
height-to-diameter ratio (H/D > 1.5 and H/D =1.5), are shown in Figure B-7 as a function of 
lithophysal porosity. It is preferred to have the height-to-width, or height-to-diameter, ratio for 
the laboratory test sample equal to or larger than 2 to minimize the effect of confinement 
resulting from friction between the loading platen and the sample. The sample to platen friction 
exerts a small radial confining stress to short-length samples, thus resulting in artificially higher 
compressive strengths. Note that the results show no relationship between shear strain at failure 
and lithophysal porosity (Figure B-7). Statistics of the results are presented in Table B-2. 
Table B-2. Summary of Statistics of Calculated Shear-Strain Increments Based on Laboratory Testing 
Number of 
Samples 
Overburden Depth Used in Calculation 
of Shear-Strain Increment (m) Mean 
Standard 
Deviation 
% % 
250 0.16 0.04 288-mm diameter, 
H/D > 1.5 
13 
400 0.17 0.05 
250 0.18 0.07 288-mm diameter, 
all 
19 
400 0.19 0.07 
Source: Appendix D, Limiting Strain  Lab Tests.xls. 
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0.00% 
0.10% 
0.20% 
0.30% 
0.40%
0% 10% 20% 30% 40% 
Porosity 
Shear Strain 
H:D > 1.5 
H:D = 1.5 
Source: Appendix D, Limiting Strain  Lab Tests.xls. 
NOTE: Shear-strain increments shown are calculated for an overburden depth of 250 m. For this case, the mean 
shear-strain increment for all 288-mm diameter samples is 0.18% strain. For the samples having a 
ratio / 1.5 H D> , which are considered the best representation of the mechanical behavior of lithophysal 
rock, the mean shear-strain increment is 0.16% (Table B-2). The bold horizontal dashed lines indicate the 
lower and upper bound of the shear strain threshold probability distribution developed in Section 6.4.3. 
Figure B-7. Calculated Shear Strain Increment for 288-mm Diameter Samples 
B2.5 SHEAR STRAIN LIMITS ESTIMATED FROM NUMERICAL RESULTS 
Numerical micro-mechanical models are used to better understand the mechanics of deformation 
and failure of lithophysal tuff and to extrapolate laboratory results to loading conditions, 
lithophysal content, and scales that could not be tested. In addition, numerical simulation allows 
full control and monitoring of the testing process (e.g., evolution of damage in the sample from 
microfractures to observable macrofractures and sample failure). The results of the existing 
numerical tests of the effect of lithophysal porosity on the mechanical properties of tuff are 
re-analyzed here to determine the strain at certain damage states. The simulations were carried 
out using PFC2D (BSC 2004 [DIRS 169930]) and UDEC (BSC 2002 [DIRS 161949]). PFC2D 
represents the rock as a bonded assembly of disks whereas UDEC represents the rock as a 
bonded assembly of polygons. The results of the numerical simulation are reported by BSC 
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ANL-MGR-GS-000004 REV 00 B-14 February 2005 
(2004 [DIRS 172334], Section 6.5) and incorporated into BSC (2003 [DIRS 166660], 
Sections 9.1 and 9.2) and BSC (2004 [DIRS 166107], Sections 7.5 and 7.6). The original reports 
provide details of the various numerical models and testing procedures. 
The numerical models of the lithophysal rock mass first were calibrated to reproduce the 
mechanical behavior observed in the laboratory compression tests on samples with a particular 
lithophysal porosity. Subsequently, the effects of changing lithophysal porosity and shape of 
lithophysae, among other factors, were investigated. Thus, it is assumed in the numerical 
analysis that lithophysal porosity and lithophysae shape are the only parameters affecting 
mechanical behavior of the lithophysal rock mass. The distribution of the lithophysae within a 
laboratory sample can also impact the strength, resulting in additional variability in test results. 
This is probably the main reason the numerical results show less scatter than what is observed in 
the laboratory tests. The numerical models, however, clearly show the controlling impact of 
lithophysal voids on strength and elastic modulus, and demonstrate the same trends in strength 
and modulus with porosity as observed in the laboratory. 
The shear-strain increments are calculated for the state of volumetric strain reversal and the 
strain state at peak stress. The PFC2D samples were tested for unconfined compression 
conditions only. An internal angle of friction of 30 was used in calculating the shear-strain 
increment based on PFC2D results. The UDEC samples were tested for both unconfined and 
confined conditions. The friction angle determined from the UDEC results was used in the 
calculating the shear-strain increment based on UDEC results. The results for three types of 2D 
simulation are superimposed on each graph shown in Figures B-8 through B-11: (a) circular 
voids, modeled by PFC2D; (b) irregular (stenciled) voids, modeled by PFC2D; and (c) circular 
voids, modeled by UDEC. Four figures are presented, corresponding to two different levels of 
confining stress (250 m and 400 m of overburden based on Wong and Silva (2004 
[DIRS 170444], p. 70) and two different assumptions about the damage state at which fracturing 
would be distinguishable in the field. 
In Figures B-8 through B-11, the engineering shear strain (axial strain minus lateral strain) 
increment for a particular state (reversal of volumetric strain rate, or peak stress) is plotted 
against lithophysal porosity. On each figure, the different symbols correspond to the three types 
of model (PFC2D circular voids-triangle symbol, PFC2D irregular voids-diamond symbol, and 
UDEC circular voids-square symbol). For the case of the state at peak stress for an overburden 
of 250 m, the shear-strain increments and standard deviations are listed in Table B-3. Although 
the UDEC and PFC2D models were calibrated to the same laboratory results, the shear-strain 
increment calculated from the UDEC results is systematically smaller than the shear-strain 
increment calculated from the PFC2D results. One reason for this is that UDEC synthetic 
sample is calibrated in such a way that its strength was slightly less than the strength of the 
PFC2D sample; at the same time, stiffness of the UDEC sample was larger than the stiffness of 
the PFC2D sample, resulting in the smaller strain increment calculated based on UDEC results. 
The other reason is that shear-strain increment based on the PFC2D results is calculated 
assuming a friction angle of 30. The shear-strain increment based on the UDEC results is 
calculated using friction angles determined from the UDEC results, which generally are larger 
than 30. In this case, smaller friction angles result in larger shear-strain increments. 
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Table B-3. Mean and Standard Deviations of Shear Strain for a Peak-Stress Criterion for Different 
Porosity Ranges; Overburden = 250 m 
Porosity Range 
PFC2D 90mm 
Circles 
PFC2D Panel Map 
Stencils 
UDEC 90mm 
Circles 
mean 0.18% 0.15% 
standard deviation 
0-5% 
0.02% 0.01% 
mean 0.16% 0.14% 
standard deviation 5%-10% 0.02% 0.02% 
mean 0.14% 0.13% 0.10% 
standard deviation 10%-15% 0.01% 0.02% 0.01% 
mean 0.15% 0.13% 0.09% 
standard deviation 15%-20% 0.01% 0.03% 0.01% 
mean 0.14% 0.14% 0.10% 
standard deviation 20%-25% 0.01% 0.03% 0.01% 
mean 0.15% 0.15% 0.10% 
standard deviation 25%-30% 0.02% 0.03% 0.00% 
mean 0.16% 
standard deviation 30%-35% 0.06% 
Source: Appendix D, Limiting Strains-Numerical Sims.xls. 
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Source: Appendix D, Limiting Strains-Numerical Sims.xls. 
NOTE: Shear strain increment determined for an overburden depth of 250 m. Numerical simulations carried out 
using software codes PFC2D and UDEC. The bold horizontal dashed lines indicate the lower and upper 
bound of the shear strain threshold probability distribution developed in Section 6.4.3. 
Figure B-8. Shear Strain Increment Determined Using the Volumetric-Strain Reversal Criterion; 
Overburden = 250 m 
0.00% 
0.05% 
0.10% 
0.15% 
0.20% 
0.25% 
0.30% 
0.35%
0% 10% 20% 30% 
Lithophysal Porosity 
Shear Strain Increment 
PFC2D+Circles 
PFC2D+Actual 
UDEC+Circles 
Volumetric Strain Reversal 
250 m Overburden
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 B-17 February 2005 
Source: Appendix D, Limiting Strains-Numerical Sims.xls. 
NOTE: Shear strain increment determined for an overburden depth of 250 m. Numerical simulations carried out 
using software codes PFC2D and UDEC. The bold horizontal dashed lines indicate the lower and upper 
bound of the shear strain threshold probability distribution developed in Section 6.4.3. 
Figure B-9. Shear Strain Increment Determined Using the Peak-Stress Criterion; Overburden = 250 m 
0.00% 
0.05% 
0.10% 
0.15% 
0.20% 
0.25% 
0.30% 
0.35%
0% 10% 20% 30% 
Lithophysal Porosity 
Shear Strain Increment 
PFC2D+Circles 
PFC2D+Actual 
UDEC+Circles 
Peak Stress 
250 m Overburden
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 B-18 February 2005 
Source: Appendix D, Limiting Strains-Numerical Sims.xls. 
NOTE: Shear strain increment determined for an overburden depth of 400 m. Numerical simulations carried out 
using software codes PFC2D and UDEC. The bold horizontal dashed lines indicate the lower and upper 
bound of the shear strain threshold probability distribution developed in Section 6.4.3. 
Figure B-10. Shear Strain Increment Determined Using the Volumetric-Strain Reversal Criterion; 
Overburden = 400 m 
0.00% 
0.05% 
0.10% 
0.15% 
0.20% 
0.25% 
0.30% 
0.35%
0% 10% 20% 30% 
Lithophysal Porosity 
Shear Strain Increment 
PFC2D+Circles 
PFC2D+Actual 
UDEC+Circles 
Volumetric Strain Reversal 
400 m Overburden
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 B-19 February 2005 
Source: Appendix D, Limiting Strains-Numerical Sims.xls. 
NOTE: Shear strain increment determined for an overburden depth of 400 m. Numerical simulations carried out 
using software codes PFC2D and UDEC. The bold horizontal dashed lines indicate the lower and upper 
bound of the shear strain threshold probability distribution developed in Section 6.4.3. 
Figure B-11. Shear Strain Increment Determined Using the Peak-Stress Criterion; Overburden = 400 m 
0.00% 
0.05% 
0.10% 
0.15% 
0.20% 
0.25% 
0.30% 
0.35%
0% 10% 20% 30% 
Lithophysal Porosity 
Shear Strain Increment 
PFC2D+Circles 
PFC2D+Actual 
UDEC+Circles 
Peak Stress 
400 m Overburden
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 B-20 February 2005 
B3. CONCLUSIONS 
The re-analysis of the laboratory results and the two sets of simulations has provided a 
correlation between mean shear-strain increment experienced by a rock mass and the damage to 
internal structures (lithophysae). This appendix provides only an analysis of the raw data 
extracted from the laboratory and numerical results. However, because it appears that no 
damage (i.e., systematic fractures around and between lithophysae) is observed at the site 
(Section 6.3 and Appendix A), the maximum shear-strain increment over the past 12.8 million 
years is likely to have been between 0.1% and 0.2%. For the 288-mm diameter samples (shown 
in Figure B-7), which are considered the best representation of the mechanical behavior of 
lithophysal rock, the majority of the results are in the range between 0.1% and 0.2% of strain. 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 February 2005 
APPENDIX C 
CALCULATION OF PEAK GROUND VELOCITIES 
FOR EXTREME GROUND MOTIONS 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 February 2005 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 C-1 February 2005 
C1. INTRODUCTION 
This analysis uses results of previous site-response modeling (BSC 2004 [DIRS 170027]) to 
determine the relation between mean horizontal peak ground velocity (PGV) at the waste 
emplacement level and the corresponding mean dynamic shear strain. This relation is used to 
transpose a shear strain threshold, which geologic and rock mechanics evidence indicates has not 
been exceeded at the waste emplacement level at Yucca Mountain (see Sections 6.3 and 6.4, 
Appendix A and B), to a value of horizontal PGV that has not been exceeded. 
Development of the relation between dynamic shear strain and horizontal PGV is subject to the 
limitations of the site-response model (BSC 2004 [DIRS 170027], Section 6.1.14). These 
limitations are 
 Two- and three-dimensional effects are not treated explicitly 
 Nonlinear behavior is treated in an approximate (equivalent-linear) fashion. 
Validation studies indicate that the model is adequate for its intended use (BSC 2004 
[DIRS 170027], Section 7). 
In addition to model limitations, some inputs to the model also have limitations. In particular, 
control motion inputs are derived from the probabilistic seismic hazard analysis (PSHA). 
Characterization of epistemic uncertainty and aleatory variability for ground motion at Yucca 
Mountain results in seismic hazard curves that increase without bound as lower and lower 
frequencies of exceedance are considered. At low frequencies of exceedance (e.g., 10-6, 10-7), 
the control motion inputs to the site-response model reach levels that are not credible (Corradini 
2003 [DIRS 171191]). For this analysis the motions are used without modification, as the 
purpose is to determine the correspondence between extreme ground motions and the shear 
strains they would generate within the site materials. 
Following this introduction, Section C2 describes the analysis to determine the relation between 
dynamic shear strain and horizontal PGV at the waste emplacement level. Section C3 
summarizes the conclusions of the analysis. 
C2. HORIZONTAL PEAK GROUND VELOCITIES AND DYNAMIC SHEAR 
STRAINS FOR THE WASTE EMPLACEMENT LEVEL 
In this section, previous results of ground-motion site-response modeling (BSC 2004 
[DIRS 170027]) are used to determine the relation between horizontal PGV and the associated 
dynamic shear strains. Site-response modeling for ground motions with annual frequencies of 
exceedance of 10-4, 10-5, 10-6, and 10-7 are used to determine the relation over a range of 
horizontal PGV and shear strain values. To obtain results for the waste emplacement level, the 
relation is based on horizontal PGV and shear strain for the average depth range of the Topopah 
Springs Tuff lower lithophysal zone. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 C-2 February 2005 
C2.1 SITE RESPONSE MODELING INPUTS 
One output of the ground-motion site-response modeling for the repository block at Yucca 
Mountain is the variation with depth of horizontal PGV and shear strain (BSC 2004 
[DIRS 170027], Section 6.3.4). That model output forms the input to this analysis to determine 
the relation between horizontal PGV and associated shear strain. In modeling site response, the 
magnitude range of earthquakes contributing to the seismic hazard for a given annual frequency 
of exceedance and uncertainties and variability in site material properties are incorporated into 
the calculations. This approach is taken to obtain site-response ground motions that have a 
hazard level consistent with the one for the input control motions (McGuire et al. 2001 
[DIRS 157510], Section 6.1). 
In implementing this approach, site-response modeling incorporates the following steps 
(BSC 2004 [DIRS 170027], Section 6.3.1): 
 Develop control motions consisting of three deaggregation earthquakes for each of 
two response spectrum frequency ranges (1 to 2 Hz and 5 to 10 Hz). 
 Develop base-case small-strain velocity profiles and dynamic material property curves 
representing epistemic uncertainty in the site characterization. 
 Using the base-case site properties, randomly develop suites of 60 profiles and curves to 
represent the aleatory variability in site properties. 
 Using the deaggregation earthquakes, determine the angle of incidence for the control 
motion. Both inclined and vertically propagating ground motions are assessed in the 
modeling. 
 Determine the site response for each combination of deaggregation earthquake, velocity 
profile, dynamic material property curves, and wave propagation type. 
As a result of implementing these steps, for each annual frequency of exceedance, the model 
outputs nominally include 2880 profiles showing the variation of horizontal PGV and shear 
strain as a function of depth. If runs fail to converge, the total number of profiles will be less for 
that case. 
Control motions forming input to the site-response model are based on the PSHA for Yucca 
Mountain (BSC 2004 [DIRS 170027], Section 6.2.2). For a given annual frequency of 
exceedance, the seismic hazard is deaggregated to identify the earthquake magnitudes and 
distances controlling ground motion for the response spectral frequency ranges of 1-2 Hz and 
5-10 Hz. To account for magnitude-dependence of the site response, three deaggregation 
earthquakes (DEAs) were developed for each frequency range to represent the range of 
magnitudes contributing to the hazard. The DEAs correspond nominally to the mean (MM), 5th 
(ML), and 95th (MH) percentile of the deaggregated hazard (with respect to magnitude only). In 
some cases, different percentiles were used to appropriately capture the magnitude distribution 
resulting from the deaggregation. Response spectra for the DEAs are scaled to match the UHS 
in the appropriate frequency range (1-2 Hz or 5-10 Hz) to maintain the appropriate hazard level. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 C-3 February 2005 
The site-response model employs a one-dimensional random-vibration-theory-based 
equivalent-linear approach (BSC 2004 [DIRS 170027], Section 6.1). The power spectral density 
of the input control motion (deaggregation earthquake) is propagated through the model. 
Random vibration theory is used to predict peak time domain values of shear strain based upon 
the shear-strain power spectrum. These values form the basis for adjusting the material 
properties of the model layers and the process is iterated until a strain-compatible solution is 
obtained. For horizontal ground motion, both inclined SV (vertically polarized shear-wave) and 
inclined and vertically propagating SH (horizontally polarized shear-wave) waves can be 
included in the modeling. In this analysis, only the results from inclined and vertically 
propagating SH waves are used. 
Site-response modeling takes into account both the uncertainty and spatial variability in site 
material properties at Yucca Mountain (BSC 2004 [DIRS 170027], Section 6.2.1). Uncertainty 
is incorporated through use of multiple base-case (mean) velocity profiles and dynamic material 
property curves (strain-dependent shear modulus and hysteretic damping). Variability is 
incorporated by use of 60 randomized representations of each base-case velocity profile and 
dynamic material property curve. For the repository block, two base-case velocity profiles (P1 
and P2) and two base case sets of dynamic material property curves (UMT=upper mean tuff and 
LMT=lower mean tuff) are used (BSC 2004 [DIRS 170027], Sections 6.2.3 and 6.2.4). 
For each of the 8 combinations of base-case velocity profile, base-case dynamic property curves, 
and wave propagator type (inclined or vertically incident), the site response is computed using 
the 6 DEAs (ML, MM, MH for 1-2 and 5-10 Hz) as the input control motion. For a given 
combination, each DEA control motion is propagated through the 60 randomized velocity 
profiles with associated randomized dynamic property curves producing 60 curves of horizontal 
PGV and shear strain versus depth. This results in a suite of 2880 curves (8  6  60) for each 
hazard level. 
C2.2 ANALYSIS OF HORIZONTAL PEAK GROUND VELOCITY AND 
ASSOCIATED DYNAMIC SHEAR STRAIN 
Using the results of the previous site-response modeling summarized above 
(MO0409MWDGMMIO.000 [DIRS 172216], and discussed in more detail in BSC (2004 
[DIRS 170027]), the analysis to determine the relation between horizontal PGV and shear strain 
consists of the following steps for each annual frequency of exceedance: 
 For each of the 8 combinations of base-case site material properties and wave propagator 
type, aggregate the results for the 3 DEAs for each frequency range. Using the 
aggregate DEA results for each frequency range, compute the median (geometric mean) 
horizontal PGV and shear strain as a function of depth for each combination. 
 For each of the 16 combinations for base case site material properties, wave propagator 
type, and frequency range, compute the average horizontal PGV and shear strain value 
over the depth range of the lower lithophysal unit of the Topopah Spring Tuff. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 C-4 February 2005 
 For each of the 8 combinations of base case material properties and frequency range, 
compute the average horizontal PGV and shear strain for the two wave propagator types. 
 For each of the 8 combinations of base-case material properties and frequency range, use 
the horizontal PGV and shear strain results for the various annual frequencies of 
exceedance to scale horizontal PGV for target shear strain values. 
In the first step, for each of the 8 combinations of base case material properties and wave 
propagation type, the results for the three DEAs associated with each response spectrum 
frequency range are aggregated. This aggregated data set forms the basis for computing median 
(geometric mean) values of horizontal PGV and shear strain as a function of depth. The medians 
are determined using the software code LOGNORM (Software Tracking Number [STN] 
10384-1.01-00) (Pacific Engineering and Analysis, 2004 [DIRS 170313]). Although the upper 
and lower magnitude DEAs are less likely, results for the three DEAs are weighted equally in 
this analysis. 
In the second step, for each of the 16 combinations of base case material properties, wave 
propagator type, and response spectrum frequency range, an average (arithmetic mean) value of 
median horizontal PGV and median shear strain is computed for the depth range of the lower 
lithophysal unit of the Topopah Spring Tuff. These average values of median horizontal PGV 
and median shear strain over the depth range of the lower lithophysal unit are used to represent 
the values of these parameters in the subsequent analyses. The depth range for the lower 
lithophysal unit was determined from the Yucca Mountain Geologic Framework Model 
(GFM2000, Data Tracking Number [DTN] MO0012MWDGFM02.002 [DIRS 153777]) using 
software code EarthVision 5.1 (STN 10174-5.1-00) (Dynamic Graphics 2000 [DIRS 167994]). 
The range was taken as extending from the average depth of the top of the lower lithophysal unit 
(951 ft [290 m]) to the average depth of the bottom of the unit (1286 ft [392 m]). Average 
depths for the unit contacts were computed for that portion of the model lying within the 
footprint of the waste emplacement area. To compute the means of the median horizontal PGV 
and median shear strain values within this depth range, the software code NORM (STN 10386- 
1.01-00) (Pacific Engineering and Analysis 2002 [DIRS 163313]) was used. 
In the third step, the results for the two wave propagator types were averaged for each of the 
8 combinations of base-case material properties and response spectrum frequency range. For 
each combination, the mean of the values for inclined and vertically propagating waves was 
determined using the commercial-off-the-shelf software code, Microsoft Excel. This step is 
documented in the workbook PGV&Strain-Average of Vertical & Inclined Results.xls 
(Appendix D) and summarized in Table C-1. 
The analysis of site-response modeling results to determine average horizontal PGV and shear 
strain values for the 8 combinations is carried out for 4 annual frequencies of exceedance (10-4, 
10-5, 10-6, and 10-7) based on results of the PSHA. To determine values of average horizontal 
PGV for other values of dynamic shear strain (i.e., 0.05, 0.1, 0.2, 0.3, 0.4, 0.5%) the fourth step 
consists of a linear interpolation/extrapolation process. This interpolation/extrapolation is 
carried out for each of the 8 combinations of dynamic material properties and response spectrum 
frequency range and documented in the workbook PGV v Shear Strain.xls (Appendix D) and 
summarized in Table C-2. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 C-5 February 2005 
These results are used in Section 6.6 to develop probability distributions for horizontal peak 
ground velocity based on an assessed triangular bounding shear strain threshold. A probability 
distribution is determined for each combination of material properties and response spectrum 
frequency range. 
C3. CONCLUSIONS 
The results of the model calculations provide a link between the shear-strain threshold 
determined in Section 6.4 of the main report and the level of horizontal PGV that would be 
needed to reach that threshold. An assessment documented in Section 6.6 of the main report 
provides distributions for the value of horizontal PGV that evidence indicates has not occurred at 
the waste emplacement level (Figure 6-8). The distributions (triangular) consist of 8 cases 
representing the epistemic uncertainty in site response. These distributions fall into 2 classes 
according to the dynamic material property curves used. If the lower mean tuff set of curves is 
used, the triangular distributions group together with a range from about 100 to 250 cm/sec and a 
mode of about 175 cm/sec. If the upper mean tuff set of curves is used, the four distributions 
range from about 200 to 500 cm/sec with a mode of about 335 cm/sec. In Section 6.8 these 
triangular distributions are used to develop a composite horizontal PGV hazard curve for the 
waste emplacement level. 
Table C-1. Modeled Horizontal Peak Ground Velocity and Shear Strain at the Waste Emplacement 
Level (Point B) 
APE 10-7 HSHH (Point A PGV = 655 cm/sec) 
P1 UMT P1 LMT P2 UMT P2 LMT 
1-2 Hz 
PGV 
(cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) 
Inclined 512.027 0.259 496.056 0.847 521.078 0.255 492.612 1.004 
0 degree 511.996 0.280 502.484 0.890 518.140 0.289 497.186 1.078 
Average 512.012 0.270 499.270 0.869 519.609 0.272 494.899 1.041 
P1 UMT P1 LMT P2 UMT P2 LMT 
5-10 Hz 
PGV 
(cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) 
Inclined 521.739 0.280 520.090 0.894 540.837 0.288 516.638 1.071 
0 degree 519.178 0.291 524.730 0.916 539.875 0.306 519.818 1.107 
Average 520.459 0.286 522.410 0.905 540.356 0.297 518.228 1.089 
APE 10-6 HSHH (Point A PGV = 301 cm/sec) 
P1 UMT P1 LMT P2 UMT P2 LMT 
1-2 Hz 
PGV 
(cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) 
Inclined 242.516 0.113 230.584 0.254 245.274 0.109 230.751 0.313 
0 degree 242.790 0.122 233.375 0.272 243.339 0.122 232.068 0.348 
Average 242.653 0.118 231.980 0.263 244.307 0.116 231.410 0.331 

Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 C-6 February 2005 
Table C-1. Modeled Horizontal Peak Ground Velocity and Shear Strain at the Waste Emplacement 
Level (Point B) (Continued) 
P1 UMT P1 LMT P2 UMT P2 LMT 
5-10 Hz 
PGV 
(cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) 
Inclined 246.020 0.121 236.407 0.269 250.268 0.121 234.866 0.339 
0 degree 246.387 0.127 238.988 0.283 248.750 0.132 236.496 0.363 
Average 246.204 0.124 237.698 0.276 249.506 0.127 235.681 0.351 
APE 10-5 HSHH (Point A PGV = 127 cm/sec) 
P1 UMT P1 LMT P2 UMT P2 LMT 
1-2 Hz 
PGV 
(cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) 
Inclined 110.660 0.047 103.713 0.072 112.270 0.044 105.751 0.081 
0 degree 110.680 0.053 105.249 0.081 110.536 0.052 105.893 0.098 
Average 110.670 0.050 104.481 0.076 111.403 0.048 105.822 0.089 
P1 UMT P1 LMT P2 UMT P2 LMT 
5-10 Hz 
PGV 
(cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) 
Inclined 99.268 0.049 92.650 0.069 100.268 0.047 93.678 0.081 
0 degree 99.308 0.053 93.821 0.075 99.132 0.052 94.035 0.090 
Average 99.288 0.051 93.236 0.072 99.700 0.049 93.857 0.085 
APE 10-4 HSHH (Point A PGV = 48 cm/sec) 
P1 UMT P1 LMT P2 UMT P2 LMT 
1-2 Hz 
PGV 
(cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) 
Inclined 45.234 0.018 42.754 0.022 45.605 0.017 43.819 0.021 
0 degree 45.279 0.021 51.777 0.025 44.729 0.020 43.523 0.027 
Average 45.256 0.020 47.266 0.023 45.167 0.018 43.671 0.024 
P1 UMT P1 LMT P2 UMT P2 LMT 
5-10 Hz 
PGV 
(cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) PGV (cm/s) 
Strain Syz 
(%) 
Inclined 31.592 0.015 29.489 0.017 31.587 0.015 30.075 0.017 
0 degree 31.660 0.017 29.810 0.019 31.079 0.017 29.923 0.024 
Average 31.626 0.016 29.650 0.018 31.333 0.016 29.999 0.021 
Source: Appendix D, PGV&Strain-Average of Vertical & Inclined Results.xls. 
NOTE: P1=Base-case velocity profile 1; P2=Base-case velocity profile 2; UMT=Base-case dynamic material 
property curve set 1; LMT=Base-case dynamic material property curve set 2; PGV=Horizontal peak ground 
velocity. 
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 C-7 February 2005 
Table C-2. Modeled and Interpolated/Extrapolated Horizontal Peak Ground Velocity for Shear Strain Values 
Annual 
Frequency of 
Exceedance 
(1/yr) 
Velocity Profile P1 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P1 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P2 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P2 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled Shear 
Strain (Syz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(Syz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(Syz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(Syz, %) 
1  10-4 45.26 0.020 47.27 0.023 45.17 0.018 43.67 0.024 
1  10-5 110.67 0.050 104.48 0.076 111.40 0.048 105.82 0.089 
1  10-5 242.65 0.118 231.98 0.263 244.31 0.116 231.41 0.331 
1  10-7 512.01 0.270 499.27 0.869 519.61 0.272 494.90 1.041 
Velocity Profile P1 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P1 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P2 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P2 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled Shear 
Strain (Syz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(Syz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(Syz, %) 
Modeled 
Horizontal 
Peak Ground 
Velocity 
(cm/sec) 
Modeled 
Shear Strain 
(Syz, %) 
1  10-4 31.63 0.016 29.65 0.018 31.33 0.016 30.00 0.021 
1  10-5 99.29 0.051 93.24 0.072 99.70 0.049 93.86 0.085 
1  10-5 246.20 0.124 237.70 0.276 249.51 0.127 235.68 0.351 
1  10-7 520.46 0.286 522.41 0.905 540.36 0.297 518.23 1.089 
Source: Appendix D, PGV v Shear Strain.xls
Peak Ground Velocities for Seismic Events at Yucca Mountain, Nevada 
ANL-MGR-GS-000004 REV 00 C-8 February 2005 
Table C-2. Modeled and Interpolated/Extrapolated Horizontal Peak Ground Velocity for Shear Strain Values (Continued) 
Velocity Profile P1 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P1 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P2 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Velocity Profile P2 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 1 to 2 Hz 
Target Shear 
Strain Values 
(Syz, %) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
0.05 110.67 76.09 115.92 68.38 
0.10 208.44 120.67 213.93 111.34 
0.20 388.85 188.96 392.95 163.43 
0.30 566.06 248.31 568.86 215.52 
0.40 743.27 292.46 744.78 257.18 
0.50 920.48 336.60 920.69 294.27 
Velocity Profile P1 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P1 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P2 + Upper 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Velocity Profile P2 + Lower 
Mean Tuff Dynamic Material 
Property Curves + 5 to 10 Hz 
Target Shear 
Strain Values 
(Syz, %) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
Interpolated/Extrapolated 
Horizontal Peak Ground 
Velocity (cm/sec) 
0.05 97.74 67.48 100.73 58.98 
0.10 198.04 113.13 197.97 101.63 
0.20 375.26 183.91 374.89 155.04 
0.30 545.08 248.56 545.47 208.44 
0.40 714.90 293.83 716.06 254.44 
0.50 884.72 339.09 886.64 292.73 
Source: Appendix D, PGV v Shear Strain.xls