bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Prediction of Fracture Fatigue Parameters from Creep Testing of Soil Cement
Authors: Kim Y , Little DN 
Published: February 2009

Abstract
When a cement-treated base layer is subjected to repeated stress, inherent microcracks begin to propagate and coalesce from the bottom of the layer and finally cause the layer to fail. In order to identify the rate of fatigue failure of the cement-stabilized base layer, Paris' law, da/dN = A(ΔKmax)n, can be used.
In this research, the parameters, A and n, were predicted by a viscoelastic approach. Uniaxial tensile creep tests were performed, and the creep versus time data were represented by means of the generalized power law, D(t) = D0 + D2tm. This power form represents the creep response of soil cement much better than the pure power law, D(t) = D1tm, because of the large initial elastic strain. Schapery's crack growth theory in linear viscoelastic media, based on the classical correspondence principle plus Laplace transform inversion, was utilized to express A and n in terms of measured creep parameters and simple material properties. These predicted parameters were compared with those developed empirically at different cement contents and curing ages. Plots of log A versus n were used to verify the validity of the viscoelastic approach to the fatigue failure criteria.
Cone Penetration of Partially Saturated Sands
Authors: Hryciw RD , Dowding CH 
Published: February 2009

Abstract
A laboratory study of cone penetration through partially saturated sand was conducted. A new method for preparing specimens at various degrees of saturation, which utilizes pressure release from previously carbonated water, is described. In closed water systems, where capillary tensions increase effective confining pressures, penetration resistance was significantly higher than in either dry or saturated conditions. Conversely, in closed-gas systems the penetration resistance was slightly lower than at full saturation.
An Alternative Method for Determining the Membrane Penetration Correction Curve
Authors: Lin H , Selig ET 
Published: February 2009

Abstract
Test results show that the previously used linear relationship between the unit membrane penetration and logarithmic effective confining pressure has limitations at low confining pressure. An alternative method is described, based on a hyperbolic type of curve fitting, which can provide more suitable membrane penetration correction curves for various initial confining pressures. An example is given of triaxial strain path test results corrected using both the logarithmic and hyperbolic methods.
Compaction Control and the Index Unit Weight
Authors: Poulos SJ 
Published: February 2009

Abstract
Procedures for measurement of percent compaction and several related practical issues are discussed. When measuring percent compaction, the “maximum” unit weight should be determined for each field unit weight test or nuclear unit weight measurement because minor differences in gradation and grain shape that are neither visually observable nor apparent from conventional gradation tests can have a significant effect on the “maximum” unit weight. A one-point compaction test should be performed as a minimum in most cases to reduce errors and the number of tests needed, to help focus on the soil type, and to help reduce conflicts with contractors.
It would be very desirable to standardize on the use of only one compaction test for all types of construction control. Use of multiple compaction tests in specifications for various fill types causes confusion in practice without adding any complementary benefit.
ASTM Test Method for Moisture-Density Relations of Soils and Soil-Aggregate Mixtures Using 10-lb (4.54-kg) Rammer and 18-in. (457-mm) Drop (D 1557) is the test preferred by the author for controlling fill in dam embankments, building foundations, highways, and other fills and for establishing the degree of compaction of natural soils. Since the “maximum” unit weight is not a true maximum, it is suggested that the value measured with the selected standardized test be referred to as the index unit weight (IUW).
Field unit weight tests for compaction control should be done within one layer, below surface disturbance, and in representative locations. Compaction test procedures for measurement of the index unit weight of clean sands and a discussion of the effects of grain breakage are presented.
The Thawed Strength of Soil Compacted While Frozen: An Introductory Study
Authors: Graham J , Fensury H , Shields DH 
Published: February 2009

Abstract
In the northern United States and in Canada, expensive earthmoving equipment usually stands idle during winter months. Considerable overall economies would result if soil could be excavated, transported, and recompacted while frozen. If engineers are to accept winter operations with frozen soil, the soil after thawing should have a strength that approaches that of the same soil worked while unfrozen. This paper examines the strength of soil that is compacted while frozen and then thawed before shearing and compares it with the strength of the same soil compacted in an unfrozen state and never frozen.
The thawed strength of frozen-while-compacted soil depends on its density, and therefore on the size, shape, and strength of the lumps of frozen soil and on the compactive effort. The influence of density (and indirectly the influence of compactive effort) on a thawed sand, a thawed silt, and a thawed clay are clearly outlined here. Work remains to be done to find the optimum frozen lump size and shape for each soil type and temperature, and then to develop the machinery needed to produce the optimum lumps in the field in winter.
Influence of Apex Angle on Cone Penetration Factors in Clay
Authors: Silvestri V , Fahmy Y 
Published: February 2009

Abstract
The present laboratory study investigates the effect of varying the apex angle on cone penetration resistance in clay. In order to reduce the cost associated with the field sampling of large blocks of sensitive clay, an artificially cemented material was conceived and tested. Steady cone penetration tests were carried out in 200-mm-diameter by 1000-mm-long cylinders of artificial clay. The 10-mm-diameter cones used were characterized by apex angles of 7.5, 15, 18, 22.5, 30, 45, 60, 90, and 180°. Penetration resistance factors Nc were obtained for each cone. The results show that the values of these factors are much larger than those predicted by existing theoretical approaches.
Pile Skin Friction in Sands from Constant Normal Stiffness Tests
Authors: Tabucanon JT , Airey DW , Poulos HG 
Published: February 2009

Abstract
Many interface and sand-to-sand direct shear tests have been performed with a constant normal stiffness to investigate the effects of interface roughness, normal stiffness, soil relative density, initial normal stress, and cyclic displacement amplitude on the soilinterface response. It is demonstrated that the patterns of behavior in these tests are similar to those observed in model pile tests and that the constant normal stiffness (CNS) condition is required to account for the effects of the volume changes that occur as soil adjacent to a pile is sheared. In dense sands that tend to expand in volume when sheared, the shear and normal stresses developed are significantly higher than for constant normal load (CNL) conditions and increase with higher values of normal stiffness. For loose sands that compress when sheared, the stresses are lower than in CNL tests and decrease for higher values of normal stiffness. The CNS tests replicate the reduction in shear stress during displacement-controlled cycling and the subsequent loss of capacity reported for model and full-scale piles. The reduction of skin friction during cycling and the subsequent loss of pile frictional capacity is found to be greatest for loose sands, high normal stiffness, large displacement amplitudes, and rough interfaces.
Measurement of In Situ Density of Sand in a Chamber by Using a Thermal Conductivity Penetrometer
Authors: Singh G , Das BM , Chong MK 
Published: February 2009

Abstract
Reliable in situ testing during soil exploration is of great help to geotechnical engineers in design considerations. This paper describes the theory and the laboratory test results for determination of the density of a sand with a quasi-static penetrometer by measuring its thermal conductivity. Effects of disturbance caused by the penetrometer have been studied. It is shown that it is possible to obtain the density of sand by precalibrating the penetrometer.
Apparatus and Procedure for an In Situ Collapse Test
Authors: Mahmoud HHH , Houston WN , Houston SL 
Published: February 2009

Abstract
Procedures for plate load testing in both shallow pits and at the bottom of a borehole are presented with descriptions of the required apparatus. The procedures were developed for collapsible soils but are expected to be useful for swelling soils as well. A key feature of the new procedures is that the wetted bulb of soil under the plate is controlled and its depth is measured at the end of the test. This makes it possible to limit the range of strains in the wetted zone and to calculate the average strain. Research by the authors presented elsewhere led to the development of influence factors that allow computation of the average stress in the wetted zone. The average stress versus average strain derived from the test for the wetted condition is of the same form as that derived from a laboratory collapse test. The in situ collapse tests presented possess certain advantages over lab tests including (a) lesser disturbance effects, (b) the ability to test difficult-to-sample soils, and (c) a degree of wetting likely to be close to that achieved in the prototype. The required apparatus is simple and can be constructed at low cost by most geotechnical firms.
Investigation of Vibration-Induced Settlement Using Multifactorial Experimental Design
Authors: Kim D-S , Drabkin S 
Published: February 2009

Abstract
A prediction model of vibration-induced settlement on granular soils was developed using multifactorial experimental design (MED). Major factors affecting vibration-induced settlement such as vibration amplitude, deviatoric stress, confining pressure, soil gradation, duration of vibration, moisture content, and relative density were considered in this study.
To accommodate all these factors, a special vibratory frame was designed to shake a soil specimen within a triaxial cell. MED allowed the authors to investigate the effect of many factors affecting vibration-induced settlement using a relatively small number of experiments. Detailed procedures for applying MED are discussed.
Low to medium vibration amplitudes with peak particle velocities ranging from 2.5 to 18 mm/s were evaluated for the settlement potential assessment. The most significant factors affecting vibration-induced settlement were vibration amplitude, confining pressure, and deviatoric stress. At a given vibration amplitude, the settlement was substantially reduced with increasing confining pressure. Vibration-induced settlement was affected by the stress anisotropy, and maximum settlement occurred at a given confining pressure in the range of earth pressure coefficients between 0.45 and 0.6.
A New Fall Cone Device for Measuring the Undrained Strength of Very Weak Cohesive Soils
Authors: Zreik DA , Ladd CC , Germaine JT 
Published: February 2009

Abstract
A new fall cone device capable of measuring undrained shear strength of extremely soft cohesive soils is described and evaluated. The Automated MIT Fall Cone has a unique mechanical counterweight system that enables the use of effective cone weights as low as 0.005 N. This weight is an order of magnitude lower than possible with a standard fall cone apparatus. The new device also uses a data acquisition system to record cone penetration versus time throughout the test. An extensive experimental program was performed on a remolded marine clay (Boston Blue Clay) to evaluate the new fall cone apparatus. The program includes measurements of cone velocity and penetration to study the dynamics of the new device. The cone velocities and penetration times agree with theoretical predictions that account for the inertia of the counterweight system. The experimental program includes strength measurements using various cone weights and geometries to check the validity of the strength-penetration relationships over a wide range of liquidity index values (0.75 to 5.6).
Soil Air Permeability: Threshold Gradient and Anisotropy
Authors: Sinha N , Rodeck SA , Omar MT , DeVantier BA , Das BM 
Published: February 2009

Abstract
In this study, a triaxial confinement chamber and mass flow meter were used to measure the air permeability of compacted clayey sand specimens. Specimens were extracted at different angles with respect to the vertical direction to measure the anisotropy. The soil was compacted at high water contents below the optimum.
At lower gradients, deviations from Darcy's law were observed. Threshold gradients were found below which the flow rate-gradient relationship was nonlinear and flow was very small. Measurements of anisotropy in air permeability revealed an order of magnitude difference in permeabilities of the specimens extracted at 0 and 90° with respect to the direction of compaction. The square root of permeability varied in the principal directions according to an ellipse function, although there was significant scatter about the ellipse. The air permeability values obtained from these tests were consistent with previously published results.
Effect of Boundary Conditions Upon Centrifuge Experiments Using Ground Motion Simulation
Authors: Whitman RV , Lambe PC 
Published: February 2009

Abstract
Two containers were used to hold a simulated stratum of sand during dynamic base shaking experiments aboard a centrifuge: a stack of rings and a box with rigid walls. Criteria for a satisfactory stacked-ring device are discussed, and details are presented for the design adopted. Results from several series of tests using stacked rings with different dimensions and aspect ratios are examined. While the overall performance of the stacked-ring confinement is satisfactory, there is evidence of deviations from the condition of simple shear, and also of arching. Almost certainly the rings did not exactly follow the motions of the soil. A few results are presented from tests using a box as the soil container. There is evidence that even distant walls can influence results when liquefaction phenomena are being observed.
Characteristic Threshold and Infrared Vibrothermography of Sand
Authors: Luong MP 
Published: February 2009

Abstract
Rheological properties of granular soils under vibratory, cyclic, and transient loading can be interpreted at the grain level where the solid particles interact with one another. Macroscopic deformations result mainly from the principal following mechanisms: (1) compaction mechanism that forces the solid particles closer together and leads to a denser packing; (2) distortion mechanism governed by irreversible grain slidings generating heat; and (3) attrition mechanism caused by breakage of asperities and crushing of grains under high pressures.
The infrared vibrothermography used in our laboratory is a nondestructive test that allows records and observations in real time of heat patterns produced by the dissipation of energy caused by friction between grains. Such dissipative heat occurs when granular soil is subjected to vibratory loading exceeding the characteristic threshold, and it shows with evidence the distortion mechanism.
The infrared thermographic technique described, which couples mechanical and thermal energy, offers the potential of directly monitoring the stress state of particle rearrangement or characteristic threshold and predicting the macroscopic mechanical response of granular materials.
Suggested Method for Performing the Flat Dilatometer Test
Authors:   ASTM Subcommittee 18.02
Published: February 2009

Abstract
The ASTM Committee D18.02 on Sampling and Related Field Testing for Soil Investigation, with Mr. Ralph Brown as Chairman, requested that this proposed Standard Method be published herein to provide exposure and to solicit comments from users. The objective is to improve its accuracy, usefulness, and acceptability, when in the future, Committee D18.02 hopes to submit it for publication in the ASTM Book of Standards. Comments should be sent to John H. Schmertmann, Chairman Committee D18.02.10. The Committee will consider all critical comments that include specific suggestions for improving the accuracy, usefulness, or acceptability of the proposed method.
New Equipment and Techniques for Use with the Cambridge Self-Boring Pressuremeter
Authors: Davidson JL , Bloomquist DG 
Published: February 2009

Abstract
New equipment and techniques for use with the Cambridge self-boring pressuremeter have been developed. These include a trailer mounted rig, which supports and transports all the equipment necessary to penetrate the self-boring pressuremeter to test depth, a self-casing technique for use in cohesionless soils where there is a danger of borehole collapse, a portable cassette unit for recording field data and dumping to a main computer, and a data reduction program.
Assessment of Damage to Geomembrane Liners by Shredded Scrap Tires
Authors: Reddy KR , Saichek RE 
Published: February 2009

Abstract
This paper presents the results of a field and laboratory study performed to assess damage to the geomembrane liner caused by using shredded scrap tires as a leachate drainage layer material in landfills. The field testing was performed to assess the damage that occurred to the geomembrane liner during construction and included nine tests conducted with different combinations of tire chip size and thickness, both with a geotextile and without a geotextile overlying the geomembrane, and under different loading conditions. The laboratory testing was performed to characterize the shredded tires, particularly their size distribution, hydraulic conductivity, compressibility, and chemical resistance. The laboratory testing also included performing simulation testing to determine the extent of damage that occurs to the geomembrane liner by the shredded tires under long-term waste-loading conditions. The damage that occurred to the geomembrane liners in both field tests and simulated laboratory tests was determined by visual observations as well as by conducting multi-axial tension tests, wide strip tension tests, and water vapor transmission tests on the exhumed geomembrane samples. Based on these results, a 0.46-m (18-in.)-thick layer of secondary shred tire chips, with an average size of 7.6 cm, placed over a 543-g/m2 (16-oz/yd2) geotextile installed over a geomembrane liner using low-ground-pressure (&lt;58 kPa) equipment was determined to provide adequate protection to the geomembrane liner during construction. The degree of protection offered under long-term loading conditions depends on the normal stress and the random orientation of the shredded tire chips at the geomembrane interface.
Constant Volume Ring Shear Apparatus
Authors: Stark TD , Contreras IA 
Published: February 2009

Abstract
The paper describes a constant volume ring shear apparatus that allows the measurement of the undrained peak and residual shear strengths of cohesive soils. The undrained peak and residual strengths are applicable to seismic stability evaluations of slopes comprised of or founded on cohesive soil. The constant-volume ring shear apparatus is equipped with a mechanism to adjust the normal stress during shear and a new specimen container that allows undisturbed specimens to be trimmed directly into the container. The normal stress is adjusted during shear such that the height of the soil specimen remains constant. This results in a constant volume or undrained shear condition. The results of constant volume ring shear tests on normally consolidated Drammen clay are compared with the results of undrained direct simple shear tests. The comparison reveals that the undrained peak shear strength obtained using the constant volume ring shear and direct simple shear apparatuses are in agreement. However, the constant-volume ring shear apparatus allows the measurement of the undrained residual strength because it permits unlimited continuous shear displacement.
On Large-Scale Model Testing of Laterally Loaded Drilled Shafts in Sand
Authors: Agaiby SW , Kulhawy FH , Trautmann CH 
Published: February 2009

Abstract
An extensive large-scale laboratory model testing program was developed to assess the behavior of drilled shafts under lateral and moment loading. Because of the large scale of the testing, little information was available in the literature on sand deposit and test preparation or on test conduct and monitoring. In this paper, guidance is presented on these preparation and testing issues, and typical results are presented to illustrate the variability of the test results.
Advances in Conductometric Phase Transition Porosimetry
Authors: Gunnink BW 
Published: February 2009

Abstract
The paper describes advances in conductometric phase transition porosimetry (CPTP) test methods and procedures for measuring the pore size distribution of soil. Included are test methods and procedures for (1) measuring the “throat or neck” size distribution using CPTP cooling data, (2) measuring soil pore structure anisotropy using radial and axial CPTP test cells, and (3) measuring the pore size distribution of soil saturated with saline pore water. Test results are presented and discussed for each of these three advances. Some of the advantages of CPTP are that: (1) it is not necessary to dry specimens prior to testing, (2) it is possible to test relatively large specimens, (3) it is possible to investigate pore structure anisotropy, and (4) it is possible to measure the pore size distribution of specimens saturated with a variety of solutions. Some disadvantages are that: (1) saturation of specimens must be 100%, (2) pore size distribution is relative, thus an independent measure of total porosity in necessary, (3) maximum measurable pore size is about 1 μm, and (4) testing time is relatively long, about two days.
Laboratory Evaluation of Horizontal Stress in Overconsolidated Sands
Authors: Abdi H , Garga VK 
Published: February 2009

Abstract
This paper describes a method for the determination of in situ horizontal stresses of heavily overconsolidated sands using a stress-path triaxial apparatus. This method was proposed by Garga and Khan (1991), who applied it to overconsolidated clays. The proposed method is based on the concept that if the radial stress exceeds the in situ horizontal stress while maintaining the axial stress constant and equal to the in situ vertical effective stress, only then will the specimen experience significant axial strain.
In this investigation, the above method was applied to specimens of known stress histories of overconsolidated sand. Simulation of complex stress histories was carried out by subjecting the soil specimens to one and two cycles of loading in drained conditions (rate of loading or unloading: 0.05 kPa/min). It was found that the proposed method replicated the simulated in situ horizontal stress exactly. The technique is capable of estimating K0 irrespective of the previously imposed stress history.