bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Approach to Measuring Dilatancy in Saturated Sands
Authors: Campanella RG , Kokan MJ 
Published: February 2009

Abstract
The determination of in situ properties of sand has proven to be a difficult objective, especially when it includes assessing volume change characteristics like dilatancy. Difficulty in obtaining representative undisturbed specimens as well as problems with extrapolating laboratory test results to the field has caused many to place increased reliance on in situ testing. One such test that is continuing to gain acceptance is the piezocone penetration test (CPTU). While the CPTU is particularly good for stratigraphic detailing and evaluating many geotechnical parameters, the assessment of volume change characteristics is, as yet, not well defined.
A new approach has been developed which uses the measurement of bulk soil resistivity, a geophysical technique, to evaluate in situ dilatancy characteristics of sand. The method makes use of a module mounted behind a standard piezocone to measure resistivity. The interpretation is based on the resistivity contrast between remolded sand at constant volume conditions and relatively undisturbed sand. These measurements are recorded continually along with the usual CPTU data and are therefore logging the dilatancy characteristics at high-depth resolution. A discussion of the method of analysis, assumptions, and limitations is given, and typical results are presented and compared. To date the results suggest that the method developed does not require groundwater sampling or laboratory testing, an obvious advantage. Thus, a dilatancy parameter is measured in combination with the CPTU identified soil stratigraphy and geotechnical properties, and all data are obtained at the same speed and reliability.
Influence of Test Chamber Boundary Conditions on Sand Bed Response
Authors: Al-Douri RH , Hull TS , Poulos HG 
Published: February 2009

Abstract
Two series of tests were performed on calcareous and silica sands in different test chamber sizes and with different base conditions to investigate the influence of test chamber boundary conditions on model pile foundation behavior.
The first series of tests investigated the effects of shear resistance between the soil and the internal wall of the test chamber upon the distribution of vertical stress down the chamber, which in turn influences the behavior of model foundations tested in the sand bed. The measured values of the vertical stress developed at the base of the sand bed show good agreement with theoretical predictions. The second series of tests studied the surface deflection of calcareous sand in the largest of the chambers during consolidation and also during the process of foundation loading. The results of this series of tests have been compared with results from other published data and are found to be in reasonable agreement.
Time-Dependent Triaxial Relaxation Behavior of a Resedimented Clay
Authors: Sheahan TC , Ladd CC , Germaine JT 
Published: February 2009

Abstract
The paper describes the results of K0 consolidated-undrained triaxial compression relaxation tests on resedimented Boston Blue Clay (BBC) using a computer-automated triaxial apparatus. Specimens were either normally consolidated (overconsolidation ratio, OCR = 1) or had an OCR = 4, and they were sheared at different axial strain rates to axial strains (εa) from 0.1 to 15%. Each strain level was maintained until the monitored shear stress and pore pressure reached equilibrium levels. The results show that a single specimen can be used reliably for multiple relaxation tests. During relaxation, the rate of normalized shear stress decay with log time, (−Δq/σ′vm)/Δlogt, is approximately constant, regardless of εa or OCR. Changes in shear-induced pore pressure during relaxation were negligible except when specimens were rapidly sheared. Independent of OCR, end-of-relaxation equilibrium stress states for relaxation strains εa ≤ 1.5% lie on a line of obliquity defined by K = σ′h/σ′v = 0.50, compared to K0 = 0.49 for OCR = 1 BBC; whereas, for εa ≥ 2.5%, the equilibrium states lie on a steeper obliquity line defined by K = 0.40.
Instrumentation for a Weigh In Motion System Using Pavement Strain
Authors: Marsh JG , Jewell RJ 
Published: February 2009

Abstract
A line of vertical strain transducers installed at a depth of 500 mm in a dense sand subgrade across one wheel path of the left hand lane of a busy highway was used to measure vehicle weights. The strain transducers, the custom-made LVDTs they incorporate, the method of installation, and the data acquisition system are described.
Expansion Potential of Compacted Fine-Grained Soils Using Suction Measurements
Authors: Garbulewski K , Zakowicz S , Karim Al-Helo I 
Published: February 2009

Abstract
Fine-grained soils in arid climates are most often unsaturated. If such soils have a swelling potential, their expansive pressure must be determined for structural design. Hitherto employed swelling test methods are time consuming and not reliable. Testing methods based on suction potential measurements are being introduced in order to evaluate the expansive potential.
Swelling test results on three fine-grained soils are described in the paper. Two testing systems were used: (1) a traditional method of constant soil volume and (2) a proposed method utilizing suction pressure measurements. The tested soil samples were characterized by different consolidation initial-moisture-content conditions. The test results presented herein were used to develop a mathematical relationship between expansive pressure and suction pressure for a given soil. A design procedure for estimating swelling pressure is proposed in the paper.
Test Procedures to Evaluate Absorption and Swelling of Grout
Authors: Krizek RJ , Borden RH 
Published: February 2009

Abstract
Described in this paper are test procedures and resulting data used in the laboratory to evaluate the absorption of water and the swelling pressures of several different mixtures of a particular acrylate grout when placed in situ. The water absorption characteristics were determined for both neat grout and grouted sand under conditions of either free swell or moderate confinement. Swelling pressures were assessed primarily by measuring the vertical stress required to prevent vertical swell under conditions of lateral constraint, but consistent data from a few different tests were found to provide supporting evidence. An interesting aspect of this study is that two separate test programs were undertaken simultaneously, but independently, in two different laboratories, and the results became known and were shared only after the testing was essentially complete. The data show that (a) a grouted sand manifests a much lower tendency to swell and absorb water than a neat grout, (b) moderate confinement under the equivalent of a meter or so of overburden significantly reduces the tendency of either neat grout or a grouted sand to absorb water and swell, and (c) the swelling behavior of a grouted sand cannot be predicted from a knowledge of the swelling behavior of the neat grout. Although the test procedures explained herein were applied to only one particular grout type for illustrative purposes, they are generally applicable to any grout or grouted soil that manifests swelling tendencies.
Moisture Increase in Expansive Soils at Developed Sites
Authors: Sikh TS 
Published: February 2009

Abstract
The purpose of this paper is to provide information pertinent to post-development depth-of-moisture increase in expansive soils underlying developed sites. In southern California, the developments are generally accompanied by irrigation around buildings and other improvements. Local experience indicates that the major source of water that contributes to moisture variation in expansive soils is heavy surface irrigation to support lush landscaping. Recent findings indicate that irrigation produces an equivalent annual rainfall of about 178 cm. In contrast, for example, the natural annual rainfall in the San Diego area is about 28 cm. Accordingly, at developed sites, the change in moisture content in soils underlying developed sites does not necesssarily follow a typical seasonal or cyclic pattern. Consequently, the main problem in this region is generally soil swell rather than shrinkage. Due to the introduction of moisture into the subsurface soils on a relatively regular and constant basis, the upper soil profile undergoes an increase in moisture content to a certain depth. Ultimately, at certain times after the completion of the construction, the moisture content stabilizes and becomes nearly constant with depth. The data from six developed sites were evaluated. These sites were developed about 10 years ago. The data indicate that the depth of moisture change was approximately 2 to 3.5 m. The climatic rating (Cw) of the southern California region is about 15, and the Thornthwaite Moisture Index (TMI) generally ranges between +20 to −40, which is similar to many other parts of the country and the world.
Rigid Plate Settlements on Soils with Varying Deformation Properties
Authors: Reznik YM 
Published: February 2009

Abstract
The need to reliably predict foundation settlements has led to the use of plate-loading tests as a method of in situ determination of soil-deformation properties. The results of bearing-plate tests, especially when presented in graphical form, serve as a way to estimate allowable pressures and deformation moduli calculations. The magnitudes of plate settlements and the configurations of plate load-settlement curves determine decisions as to the acceptance of certain types and dimensions of foundations. This paper describes settlements of plates/experimental footings on soils in which deformation properties improve with increasing depth. A simple interpretation formula is offered to calculate allowable pressures. The application of this formula is demonstrated in plate-load test results published in the literature. Erratum to this paper appears in 18(3).
Effects of Sustained and Repeated Tensile Loads on Geogrid Embedded in Sand
Authors: Min Y , Leshchinsky D , Ling HI , Kaliakin VN 
Published: February 2009

Abstract
Design methods for reinforced soil structures under static loading conditions are relatively well established. Little research has been conducted on the behavior of embedded geosynthetics subjected to repeated loadings. Such research is needed to improve the design of reinforced soil structures subjected to traffic and seismic loadings. The study reported here is related to the long-term performance of a geogrid embedded in Ottawa sand under several confining pressures and subjected to various tensile loads. Different magnitudes of sustained and repeated tensile loads were applied to the geogrid incrementally using a pullout device. The confining pressure increased the soil-geogrid interface friction force and thus affected strain distribution along the geogrid length. Creep developed in the geogrid as the applied tensile load increased. The geogrid creep strain rate at a given tension force was found to be independent of confining pressure at the point of this force application, that is, creep can be viewed as an intrinsic property of the geogrid. A rapid pullout failure of geogrid occurred as the applied sustained load approached the ultimate pullout capacity. Conversely, under repeated loading the pullout occurred progressively. The ultimate pullout load and interaction coefficient, Ci, obtained from repeated loading tests were about 20% less than the values obtained from sustained loading tests. This suggests that a Ci smaller than that obtained in static (conventional) tests should be used in structures subjected to dynamic load. Creep under repeated load was smaller than that under sustained load.
Geotechnical Properties of Municipal Solid Waste
Authors: Gabr MA , Valero SN 
Published: February 2009

AbstractA geotechnical testing program was conducted to evaluate the engineering properties of aged solid waste samples retrieved from a landfill that began accepting waste as early as 1940. The conducted tests included water content, specific gravity, Atterberg limits, grain-size distribution, compaction, permeability, consolidation, triaxial, and direct shear. Maximum dry unit weight achieved using the Standard Proctor Test was approximately 9.3 kN/m3 at a water content of 31%. Compression Index values, Cc, derived from small-scale (63.5 mm in diameter), one-dimensional consolidation tests were between 0.4 and 0.9 for a void ratio range of about 1.0 to 3.0. Secondary Compression Index values, Cα, appeared to be less dependent on initial void ratio and more dependent on conditions favorable to microbial activity and were estimated to range between 0.009 and 0.03. Total strength parameters from consolidated undrained (CU) triaxial tests yielded a range of cohesion values, c, of about 100 kPa at w of 55% to 40 kPa at w of 72%. Apparent effective strength parameters were evaluated as an effective friction angle, φ', of 34° and an effective cohesion of 16.8 kPa. Results from direct shear tests at different levels of horizontal displacement indicated that the value of the friction angle increased with the displacement level while cohesion remained essentially constant. Effective friction angles, φ', of 20.5 to 39° with c' of 27.5 to 0 kPa were evaluated from the direct shear tests. In general, results from this study were comparable to those reported in the literature and obtained from laboratory, field, and large-scale unconventional tests. However, the apparent effective strength parameters evaluated from the conventional laboratory tests seem generally higher than those evaluated through back calculations. Apparent effective friction angle values evaluated in this study were as much as 10° higher than those reported in the literature and evaluated from back calculations.
A Study of Strike-Slip Faulting Using Small-Scale Models
Authors: Lazarte CA , Bray JD 
Published: February 2009

AbstractResults from tests on small-scale soft clay models subjected to strike-slip faulting in a 1-g environment are presented. Kinematic/boundary conditions and material ductility were dominant factors on model response. Material ductility significantly affected the deformation and breakage patterns in level ground and embankment models, with larger base offsets being required to produce surface offsets in ductile materials. In addition, the shear zone was broader with ductile materials. Horizontal and vertical distributions of shear deformation within the models are presented. The rate of rupture propagation appears to increase as the base fault ruptures up through the soil. The effect of model geometry and base fault orientation are also important in the model's response.
Wave Propagation in Soils: Multi-Mode, Wide-Band Testing in a Waveguide Device
Authors: Fratta D , Santamarina JC 
Published: February 2009

Abstract
This paper presents the development of a waveguide device and the corresponding processing methodology to study wave propagation in particulate materials. Its main advantages are: the cancellation of biasing transfer functions (e.g., transducer, coupling, and electronics); the determination of both velocity and attenuation in a wide frequency range; the evaluation of torsional, flexural, and longitudinal propagation modes; and the computation of field propagation parameters from laboratory multi-mode data. Fundamentals of signal processing are reviewed, followed by a discussion of design considerations including boundary effects and geometric dispersion. Typical results are presented.
Coupled Heat and Moisture Flow in Unsaturated Swelling Clay Barriers
Authors: Mohamed AMO , Yong RN , Onofrei CI , Kjartanson BH 
Published: February 2009

Abstract
The main thermodynamic forces active in the near field of a nuclear fuel waste multiple barrier system during the unsaturated stage are the gradients of temperature, fluid pressure, and chemical potentials. The processes that have a direct impact on the transport mechanism of heat and moisture within the clay-based compacted buffer material are coupled. The major problems in describing coupled heat and moisture flow (CHMF) in unsaturated swelling clay barriers are the lack of experimental data and the lack of a method to estimate CHMF diffusivity parameters (CHMF-DIPAR).
This paper presents the experimental procedures, the analysis of experimental data, and a method of determining CHMF-DIPAR. Several series of one-dimensional tests were performed to examine the transient temperature and moisture flow in buffer material compacted at a dry density of 1.67 Mg/m3 and optimum volumetric moisture content (VMC) of 0.28. CHMF-DIPAR were calculated using the measured temperature and moisture distributions combined with an analytical solution of CHMF equation and a square-root time (SQRT) technique.
High-Temperature Brazilian Test for Tensile Strength of Metamorphic Limestone
Authors: Lee D-H , Juang CH , Lei I-M 
Published: February 2009

Abstract
This technical note presents a low-cost and fast, high-temperature tensile strength test of rocks. A series of splitting tensile strength tests, the so-called Brazilian test, were conducted on metamorphic limestone specimens at high temperature using a special triaxial cell assembly that can sustain a maximum temperature of 315°C. Results of these Brazilian tests at various temperatures (30, 100, 200, and 300°C) are presented and discussed. The results show that the tensile strength of the rock decreases as the temperature of the rock increases. The reduction in tensile strength is found to be greater when the tests are actually conducted at high temperature rather than at room temperature using thermally treated specimens.
Grain-Size Distribution of Mixed Aggregates
Authors: Windisch ÉJ 
Published: February 2009

Abstract
When various aggregates are to be combined in order to obtain a mix having a desired grain-size distribution, current methods are based on a trial-and-error approach. It is shown in this paper that the process of combining various soils or aggregates may be a simple, rapid, and efficient procedure that eliminates the need for trial and error. The paper presents the formulation of the combination process as a problem of optimization and describes the steps of the proposed procedure. The solutions of some typical problems of aggregate combinations are given as examples.
Proposed Standard Test Method for Measurement of Pneumatic Permeability of Partially Saturated Porous Materials by Flowing Air
Authors: Eischens G , Swanson A 
Published: February 2009

Abstract
This proposed standard describes a laboratory test method for the measurement of the coefficient of permeability for airflow (pneumatic permeability) through porous media (e.g., soils) partially saturated with water. Control and measurement of the airflow is effected at the inlet of the specimen. The permeameter cell is fitted with dual transfer lines that isolate the specimen pressure drop from the effects of gas flow in the apparatus. Electronic instrumentation results in short test times that minimize changes in water content. This proposed standard addresses the need to develop a body of knowledge in support of soil vapor extraction (SVE) systems and allied environmental remediation activities.
A New Technique for Diffusion Testing of Unsaturated Soil
Authors: Barbour SL , Lim PC , Fredlund DG 
Published: February 2009

Abstract
A technique is proposed for determining the coefficients of diffusion and adsorption for ions in unsaturated soils. The method integrates the single reservoir diffusion testing of saturated soil with the axis-translation technique for the control of matric suction. The procedure allows for the application of a net total stress and matric suction to the soil during the diffusion test. The use of this new technique to determine the coefficients of diffusion and adsorption of ions from a single test is demonstrated. The effects of the degree of saturation on the coefficients of diffusion and adsorption were evaluated on a sandy soil with water contents ranging from saturation to near the residual degree of saturation. Potassium and chloride ions were used as the primary tracers.
The test results showed that both the coefficients of diffusion and adsorption can be determined from a single test. The results illustrate a decrease in both the effective diffusion and adsorption coefficients with a decrease in the degree of saturation. The extent of the decrease in the effective diffusion coefficient from saturation to near the residual degree of saturation was approximately 80%. The decrease in the adsorption coefficient was gradual and small from saturation to a degree of saturation of approximately 10%; however, it then decreased rapidly as the water content approached the residual degree of saturation.
Model Size Effects in Centrifuge Models of Granular Slope Instability
Authors: Goodings DJ , Gillette DR 
Published: February 2009

Abstract
Two assumptions behind geotechnical laboratory testing are: first, that soil with grains small enough to behave as a continuum in a full-scale field situation will also behave as a continuum in a small laboratory test; and, second, that side boundary effects in a laboratory test are either negligible or, if not negligible, do not dominate behavior but are quantifiable so that a correction can be made for their effects. Data are presented here from 61 centrifuge models of slopes brought to failure to assess side boundary and grain-size effects on model behavior. Three granular soils of different grain sizes were used to build models of different scales and widths. Model slopes were brought to failure by increasing self-weight, which simulates increasing full-scale height while maintaining slope geometry. To simulate the behavior of soil with cohesion, a small negative pore pressure was applied to the soils using a vacuum.
Models failed with wide, shallow slope failures. There were two effects on model behavior arising from grain size. First, it appears that the model failure “surface” may have to be more than 30 grain diameters below the soil surface before grain-size effects are negligible. Secondly, the repeatability of model results was also affected by grain size: coefficients of variation in failure data for a single group of identical models were 10% or less when slope height was 158 grain diameters or greater; coefficients of variation increased markedly for smaller model slopes with heights 56 grain diameters or less. When effects of model width were examined, it appears that model width may have to exceed model slope height by a factor of 5 for shallow wide slope failure to develop unimpeded by side boundaries.
Engineering Properties of Tire/Soil Mixtures as a Lightweight Fill Material
Authors: Masad E , Taha R , Ho C , Papagiannakis T 
Published: February 2009

Abstract
The United States Environmental Protection Agency (USEPA) estimates that over 279 million discarded tires are being added annually to the already existing stockpile of two billion tires. Current disposal and stacking methods of waste tires are not acceptable due to the possibility of fire and health hazards. Several states and the federal government have issued legislation that encourages or mandates the recycling of discarded tires. One application where shredded tires can be used is as a lightweight fill material behind retaining walls or in highway embankments over weak or compressible soils.
This paper presents the engineering properties of shredded tires, Ottawa sand, and a mixture of 50% Ottawa sand and 50% shredded tires by volume (70% Ottawa sand and 30% shredded tires by weight). The maximum size of the tire chips used was 4.75 mm. Gradation, specific gravity, void ratio, density, permeability, and consolidated-drained (CD) triaxial tests were performed as part of the testing program. Although the data obtained were limited to the above three mixes, the results indicate that the use of shredded tires/Ottawa sand mixes as a lightweight fill material is very promising. However, long-term impact of leachates from tires on groundwater quality should be investigated.