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Showing papers in "Journal of the Soil Mechanics and Foundations Division in 1973"


Journal ArticleDOI
TL;DR: In this paper, a modern outlook of the problem of bearing capacity of shallow foundations is presented, incorporating all major contributions to the subject, along with best available solutions and appropriate numerical values of bearing capacities and coefficients.
Abstract: The paper presents a modern outlook of the problem of bearing capacity of shallow foundations, incorporating all major contributions to the subject, along with best available solutions and appropriate numerical values of bearing capacity factors and coefficients. It is shown that the greatest shortcoming of available theories lies in their unreserved assumption of incompressibility of the foundation soil. An attempt is made to formulate for the first time rational compressibility criteria for soils subjected to foundation loads. A set of tentative compressibility factors, to be used with the classical bearing capacity equation, are given. The paper includes an analysis of the effects on bearing capacity of roughness and vertical profile of foundation base, ground-water table, presence of adjacent footings and rate of loading.

910 citations


Journal ArticleDOI
TL;DR: In this article, the authors presented the results of a study concerning the accuracy of displacements caused by a single, harmonic, one-dimensional elastic wave propagating through a finite element mesh.
Abstract: The purpose of this paper is presentation of the results of a study concerning the accuracy of displacements caused by a single, harmonic, one-dimensional elastic wave propagating through a finite element mesh. Results are presented for the steady-state response of a finite model of the semi-infinite elastic constrained rod; both the homogeneous and two material cases were analyzed.

896 citations


Journal ArticleDOI
TL;DR: In this paper, a cubical triaxial apparatus was used for an investigation of the influence of the intermediate principle stress on the drained stress-strain and strength characteristics of sand.
Abstract: A new type of cubical triaxial apparatus was used for an investigation of the influence of the intermediate principle stress on the drained stress-strain and strength characteristics of sand. For the same value of the minor principle stress and increasing value of the intermediate principle stress, both dense and loose specimens showed increasing slope of the stress-strain curve, decreasing strain-to-failure, and increasing rate of dilation. The strength of the sand as represented by the friction angle increased from triaxial compression to a maximum before a slight decrease at triaxial extension. Observations regarding the applicability of the normality condition of classical plasticity theory to sand were made. Expressions were derived for the variations of the friction angle in the immediate vicinity of the conditions of triaxial compression and extension, and the test results were shown to fit these expressions.

300 citations


Journal ArticleDOI
TL;DR: In this paper, the authors presented a method for dynamic stress analysis of saturated soil structures subjected to earthquake loading, where the soil was idealized as a fluid saturated porous solid and the coupled equations of motion of the finite element discretized system were solved by a step-by-step integration scheme to determine the motion of constituent materials along with the intergranular stresses and the pore pressure.
Abstract: The objective of this paper is to present a method for dynamic stress analysis of saturated soil structures subjected to earthquake loading. The soil is idealized as a fluid saturated porous solid. The coupled equations of motion of the finite element discretized system are solved by a step-by-step integration scheme to determine the motion of the constituent materials along with the intergranular stresses and the pore pressure. Finally, some results of an illustrative example of an earth dam-reservoir system are presented and analyzed.

193 citations


Journal ArticleDOI
TL;DR: In this paper, an empirical expression is developed to determine the amount of time necessary to fully saturate various samples of Ottawa sand at varying initial degrees of saturation for laboratory testing for various types of soil along with alternate methods for saturating.
Abstract: Previously published theoretical expressions relating the back pressure required to fully saturate a partially saturated soil sample with the initial degree of saturation are presented in this paper. An empirical expression is developed to determine the amount of time necessary to fully saturate various samples of Ottawa sand at varying initial degrees of saturation for laboratory testing for various types of soil along with alternate methods for saturating are also presented.

143 citations


Journal ArticleDOI
TL;DR: The mechanism of secondary compression in soils can be described in terms of changes in soil structure as mentioned in this paper, and for normally consolidated natural soils, the coefficient of secondary compressive index is influenced by such factors as time, consolidation pressure, precompression, sustained loading, remolding, shear stresses, rate of increase in effective stress, sample thickness, and temperature.
Abstract: The mechanism of secondary compression in soils can be described in terms of changes in soil structure. Instant and delayed compression are parts of the continuous process of volume change, and for normally consolidated natural soils, the coefficient of secondary compression and compression index is influenced by such factors as time, consolidation pressure, precompression, sustained loading, remolding, shear stresses, rate of increase in effective stress, sample thickness, and temperature. Of all the factors considered, precompression and sustained loading have the most important influence on the coefficient of secondary compression.

142 citations


Journal ArticleDOI
TL;DR: In this article, a generalized physical model is tested triaxially in order to relate properties of the intact material and of the discontinuities to the strength and deformability of a jointed rock mass.
Abstract: A generalized physical model is tested triaxially in order to relate properties of the intact material and of the discontinuities to the strength and deformability of a jointed rock mass. The behavior of jointed models can be divided into three characteristic zones. At low confining stresses there is either sliding along preexisting joints or brittle failure through intact material and across joints with strength depending on the number of intersected joints. At intermediate confining stressed sliding or failure may occur again, but the failure mode changes from brittle to ductile. At high confining stresses no sliding and only ductile failure occurs. The three zones and the upper and lower bounds of strength are easily obtained by a few confined compression tests on the intact material, by sliding tests along joints, and by a direct tension test. If this characteristic behavior is valid for other materials, as seems likely because of the basically similar underlying mechanism, it may become possible to determine the behavior of a jointed rock mass by relatively simple experiments.

139 citations


Journal ArticleDOI
TL;DR: In this article, an analysis for the behavior of a pile in a soil undergoing lateral movements due to some external cause such as an embankment is described, and some of the factors affecting the development of pile displacements, moments, and reactions are examined, and it is found that the most important factors are the relative flexibility of the pile, boundary conditions at the top and the tip, and the distribution of soil movement with depth along the pile.
Abstract: An analysis is described for the behavior of a pile in a soil undergoing lateral movements due to some external cause such as an embankment. Some of the factors affecting the development of pile displacements, moments, and reactions are examined, and it is found that the most important factors are the relative flexibility of the pile, the boundary conditions at the top and the tip, and the distribution of soil movement with depth along the pile. Limited comparisons between theoretical and observed pile behavior suggest that the theoretical approach could be applied with some degree of confidence to field problems.

120 citations


Journal ArticleDOI
TL;DR: In this paper, the authors compared the results of the Simplified Bishop procedure with results obtained using the finite element procedure of analysis and found that the agreement between the two procedures was closest for relatively flat slopes with relatively low values of cohesion.
Abstract: The accuracy of limit equilibrium slope stability analyses procedures is examined by comparing the results of the Simplified Bishop procedure with results obtained using the finite element procedure of analysis. The distributions of normal stresses along the shear surface were compared and found to be reasonably similar, the agreement between the two procedures being closest for relatively flat slopes with relatively low values of cohesion. The values of the factor of safety, while assumed constant in the Bishop procedure, were shown by the finite element analyses to vary considerably along the shear surface. However, the overall, or average, values of the factor of safety computed by these two procedures were found to agree within 5 percent over the range of conditions investigated. It was concluded from these results that the Simplified Bishop procedure, as well as many other limit equilibrium analysis procedures, do not involve large errors in the computed values for the overall factor of safety of earth slopes.

86 citations


Journal ArticleDOI
TL;DR: The index properties of returned lunar soils from the United States Apollo and the Soviet Luna programs are reviewed in this paper, which includes lunar soil genesis, particle types, grain size distribution, grain shape distribution, specific gravity, minimum and maximum density, and relative density.
Abstract: The index properties of returned lunar soils from the United States Apollo and the Soviet Luna programs are reviewed. The scope of the paper includes lunar soil genesis, particle types, grain size distribution, grain shape distribution, specific gravity, minimum and maximum density, and relative density. The writers also present their own data for the latter three properties, as determined on three 1-gm submillimeter lunar samples taken on Apollo 14 and 15. The lunar soils are shown to be well-graded silty sands to sandy silts, composed of many different particle types (mineral fragments, glasses, agglutinates, basalts, and breccias) all produced primarily by meteorite impacts on the lunar surface. The specific gravity varies from 2.90 to 3.24 and the minimum and maximum bulk densities vary from 0.87 to 0.10 g/cm³ and from 1.51 to 1.89 g/cm³, respectively. The in situ lunar soil can have a low relative density at the surface, increasing rapidly to a very high relative density at depths greater than 10 to 20 cm.

76 citations


Journal ArticleDOI
TL;DR: In this article, a series of tests on model anchor plates in sand are described in the form of dimensionless force coefficients and shape factors relating failure loads to the geometry of the anchor and its depth of embedment.
Abstract: There are many situations in civil engineering where vertical earth anchors must be used to withstand horizontal loading. A series of tests is described on model anchor plates in sand. The results are presented in the form of dimensionless force coefficients and shape factors relating failure loads to the geometry of the anchor and its depth of embedment. The method of stress characteristics is used to produce comparable theoretical values which agree well with experimental results at both model and field scales. The measured shape factors are independent of the size of the plate, and this contrasts with the force coefficients which decrease with increasing anchor size. A theoretical solution has been developed which allows φ to vary in a failure zone, depending on stress levels in the computations, and the effect is shown to be important. Difficulties in selecting suitable φ-values for design are outlined, and possible design procedures examined.

Journal ArticleDOI
TL;DR: In this paper, the results of analytical and laboratory studies on small reinforced earth retaining walls were compared to analytical solutions for wall failure by either pullout or breaking of the reinforcing elements, and found to be in reasonable agreement.
Abstract: Reinforced earth is a man-made earth fill in which thin bars, rods, fibers, or nets have been placed to improve the overall qualities of the soil This paper describes the results of analytical and laboratory studies on small reinforced earth retaining walls Experimental data were compared to analytical solutions for wall failure by either pullout or breaking of the reinforcing elements, and found to be in reasonable agreement Cost estimates for prototype structures suggest that the cost of reinforced earth could be as low as half the cost of other conventional earth retaining walls

Journal ArticleDOI
TL;DR: In this article, the authors compared the passive earth pressure of a vertical wall pushing into sand with a horizontal surface using the method of slices employed in slope stability work and found that the computed values compare more favorably with experimental findings for dense sand than do previous theories.
Abstract: Coefficients of passive earth pressure have been compared using the method of slices employed in slope stability work. The common problem of a vertical wall pushing into sand with a horizontal surface has been investigated. The computed values compare more favorably with experimental findings for dense sand than do previous theories. The method is simple and may be extended to problems involving sloping backfill and surcharge loading.

Journal ArticleDOI
TL;DR: In this paper, a theory to describe the simultaneous coupled diffusional flow of salt and water in soils is summarized, and a computer analysis of consolidation caused by chemico-osmotic coupling shows that the effects of coupling should increase as soil void ratio decreases and soil compressibility and salt concentration differences increase.
Abstract: A theory to describe the simultaneous coupled diffusional flow of salt and water in soils is summarized. Examination of the coupling effects indicated by the theory and a computer analysis of consolidation caused by chemico-osmotic coupling shows that the effects of coupling should increase as soil void ratio decreases and soil compressibility and salt concentration differences increase. Test results have shown that chemico-osmotic effects do not exist, and the rates of solution flow are in reasonable accord with theoretical predictions. Chemico-osmotic consolidation is likely to be small for most soils, except for very fine-grained active clays like bentonite. However, these and other studies have shown that chemico-osmotic coupling is capable of moving soil pore water and dissolved salts and that chemico-osmotic soil stabilization might be feasible in certain cases.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the behavior of the builders of a WATER TOWER, which consisted of two spherical spheres, one facing up and the other facing down, connected to a ring beam.
Abstract: THE BEHAVIOR OF SPHERICAL SHELLS USED FOR THE FOUNDATION OF A WATER TOWER WAS INVESTIGATED. A CONCRETE MODEL WAS DESIGNED ON THE BASIS OF MEMBRANE ANALYSIS SUBJECTED TO UNIFORMLY DISTRIBUTED LOADING. THE SHELL FOUNDATION CONSISTED OF TWO SPHERICAL SHELLS; ONE WITH THE CAVITY FACING UPWARDS AND THE OTHER WITH THE CAVITY FACING DOWNWARDS. THESE TWO SHELLS WERE MONOLITHICALLY CONNECTED TO A RING BEAM. THE POSITION OF THE RING BEAM IS SUCH THAT THE HORIZONTAL COMPONENT OF THE DIRECT MERIDIONAL FORCE DEVELOPED BY THE TWO SHELLS AT THE RING BEAM BALANCE EACH OTHER. MEMBRANE ANALYSIS IS CONSIDERED AND EQUATIONS ARE PRESENTED. MAJOR STEPS IN THE DESIGN OF A FOOTING ARE OUTLINED. THE OVERALL DIMENSIONS OF THE PLAN AREA IS DETERMINED BY DIVIDING THE TOTAL LOAD BY THE SAFE BEARING CAPACITY. FACTORS INFLUENCING THE PRESENT INVESTIGATION ARE OUTLINED. DETAILS ARE GIVEN OF THE MODEL DESIGN. THE FOUNDATION BASE IS DESCRIBED IN DETAIL. A 200-TON HYDRAULIC JACK WAS USED FOR TESTING PURPOSES, AND THE APPLIED LOAD WAS INDICATED BY MEANS OF A PRESSURE GAGE. A LOADING DEVICE APPLIED FOUR POINT LOADS AT THE COLUMN POSITIONS ON THE RING BEAM. OBSERVATIONS MADE ARE RECORDED AND CONCLUSIONS DRAWN ON THE BASIS OF THE STUDY ARE PRESENTED.

Journal ArticleDOI
TL;DR: In this article, the experimental program to study plane strain bearing capacities of 3-in and 6-in. model footings on dense sand is described, and it is found essential that plane strain conditions are maintained in the test box, as deflections of the walls can cause a significant reduction in the ultimate bearing capacity and lodging of sand grains between the footing and the walls.
Abstract: The experimental program to study plane strain bearing capacities of 3-in. and 6-in. model footings on dense sand is described. It is found essential that plane strain conditions are maintained in the test box, as deflections of the walls can cause a significant reduction in the ultimate bearing capacity and lodging of sand grains between the footing and the walls. Results also show that the ultimate bearing capacities for tough footings are only 10% higher than those for smooth footings and thus Meyerhof’s recommendation that 1/2 (Nγ) be used for smooth footings is not substantiated. Sokolovski’s method of solving the plasticity problem, as illustrated through the scaling procedure developed by Ko and Scott, produces the most accurate estimate of the smooth footing bearing values and appears to give a slightly conservative estimate of rough footing bearing values.

Journal ArticleDOI
TL;DR: In this article, two methods of organic content determination, ignition and wet digestion, were used and the results compared and it was found that for the soils studied, ignition at 400° C was appropriate as a test for organic content.
Abstract: The objectives are to examine the variation of these properties with organic content and to compare the behavior of mechanical mixtures with that of natural samples of comparable organic content. The effect of mineralogy is also studied to check its possible influence on mechanical behavior and on the organic content determination. Two methods of organic content determination, ignition and wet digestion, were used and the results compared. It was found that, for the soils studied, ignition at 400° C was appropriate as a test for organic content. While minor organic content had a strong influence on the compaction behavior, its effect on strength is much less than that of minor mineralogical or structural differences. Oven-drying was found to reduce the influence of the organic matter. Mixtures behave in compaction like natural samples of similar organic content.

Journal ArticleDOI
TL;DR: In this article, the solution of two-dimensional transient seepage problems under the influence of both electrokinetic and hydrodynamic forces is found using the finite element method.
Abstract: The solution of two-dimensional transient seepage problems under the influence of both electrokinetic and hydrodynamic forces is found using the finite element method. The governing differential equations account for both the time-dependent consolidation and the time-dependent storage of electricity of the soil media. Solutions to problems are primarily presented as the movement of the phreatic surface with time, but pore water velocities, hydraulic, and electric potentials at the nodes are also calculated in the program. A practical problem, where electroosmosis was used because normal dewatering methods have proven ineffective, was analyzed using the numerical model. The results obtained compared favorably with measurements made in the field. The main advantage of the numerical model is that the electrode configuration can easily be changed to enable the most efficient arrangement to be determined.

Journal ArticleDOI
TL;DR: In this paper, it was found that the strength of the LUNAR soil is less than that of a ground-basalt simulator in air, and the contrast between the two was shown to be significant.
Abstract: TWO OEDOMETER AND THREE DIRECT SHEAR TESTS HAVE BEEN PERFORMED IN VACUUM ON A 200-G SAMPLE OF LUNAR SOIL FROM APOLLO 12 (SAMPLE NO. 12001, 119). IT HAD BEEN EXPECTED THAT THE VACUUM ENVIRONMENT AND CLEAN PARTICLE SURFACES WOULD CAUSE THE LUNAR SOIL TO HAVE A LOWER COMPRESSIBILITY AND A HIGHER SHEAR STRENGTH THAN THAT OF A GROUND BASALT SIMULANT IN AIR. INSTEAD, IT IS FOUND THAT THE OPPOSITE IS TRUE: THE COMPRESSIBILITY OF THE LUNAR SOIL IS SLIGHTLY GREATER AND THE SHEAR STRENGTH IS SIGNIFICANTLY LESS. THIS DIFFERENCE IS TENTATIVELY ATTRIBUTED TO THE DEGRADATION UNDER STRESS OF FRAGILE LUNAR PARTICLES SUCH AS AGGLUTINATES AND BRECCIAS. OVER THE RANGE OF DENSITIES TESTED, THE TYPICAL VIRGIN COMPRESSION INDEX IS 0.06 AND THE FRICTION ANGLE VARIES FROM 28 DEG TO 35 DEG. LARGE-SCALE PARTICLE CRUSHING OCCURS AT NORMAL STRESSES OF LESS THAN 70 KN/SQ M (10 PSI), AND CONSEQUENTLY, THE MOHR-COULOMB STRENGTH ENVELOPE SHOULD BE EXTREMELY CURVED. THE SHEAR STRENGTH OF OTHER LUNAR SOILS AT THE SAME VOID RATIO WILL PROBABLY VARY ACCORDING TO THE PROPORTION OF FRIABLE PARTICLES. /AUTHOR/

Journal ArticleDOI
TL;DR: In this article, the effects of allowing small lateral strains and the restraining direction on the value of earth pressure at rest were examined, and the effect of small lateral strain and restraining direction was shown.
Abstract: The coefficient of earth pressure at rest can be accurately determined by conducting constant stress ratio tests in the triaxial apparatus (interpolation method). This method is stress controlled and thus the errors in strain measurements do not interfere with the test procedure and can be corrected for after the test is finished. Strains in a \IK\do\N increases with: (1) the increase in porosity, decrease in φ\dμ, crushing; and (2) the increase in the modulus of elasticity of the particles mineral. The effects of allowing small lateral strains and the restraining direction on the value of \IK\do\N are examined.

Journal ArticleDOI
TL;DR: In this paper, a numerical technique is presented for predicting the two-dimensional transient temperature distribution in freezing or thawing wet soil, which is applied in estimating the influence of seepage stream velocity on an artificial free-draining wet soil by a row of freeze pipes, and it is shown that small groundwater flows perpendicular to the vertical axis of a freeze pipe have no significant effect on the rate of growth of the ice boundary in the horizontal direction.
Abstract: A numerical technique is presented for predicting the two-dimensional transient temperature distribution in freezing or thawing wet soil The technique is applied in estimating the influence of seepage stream velocity on an artificial free-draining wet soil by a row of freeze pipes It is shown that small ground-water flows perpendicular to the vertical axis of a freeze pipe have no significant effect on the rate of growth of the ice boundary in the horizontal direction In fact, a flow on 001 cu ft per hr per sq ft to possibly 002 cu ft per hr per sq ft may even enhance the rate of propagation of the ice boundary Increases in flow above those limits diminishes the rate of growth of the ice boundary quite markedly At a flow rate of 050 cu ft per hr per sq ft, closure of the ice boundary between a row of 6-in freeze pipes with a center-to-center spacing of 86 ft will never occur

Journal ArticleDOI
TL;DR: In this article, the characteristics of earth pressure loads on buried structures due to fault movements are examined and two types of finite element analyses are described which can be used to calculate the magnitudes of these pressures.
Abstract: The characteristics of earth pressure loads on buried structures due to fault movements are examined and two types of finite element analyses are described which can be used to calculate the magnitudes of these pressures. Although the problem is three-dimensional, the results of two-dimensional analyses are shown to be consistent with the results of model tests. These analyses can be used to determine the distribution of pressures on the structure, and to estimate the magnitudes of the earth pressure loads for design of a structure subject to fault movements.

Journal ArticleDOI
TL;DR: In this article, the authors used the failure of a 90ft-high (27 m) underwater slope in San Francisco Bay to assess the accuracy of conventional laboratory and field vane shear tests for measuring the undrained strength of a normally consolidated clay.
Abstract: The failure of a 90-ft-high (27 m) underwater slope in San Francisco Bay is used to assess the accuracy of conventional laboratory and field vane shear tests for measuring the undrained strength of a normally consolidated clay. The net effect of systematic errors due to disturbance, anisotropy, cap and base restraint, and the use of triaxial rather than plane strain tests was apparently small in this case, but the reduction of undrained strength due to creep under continued loading was significant, and the effect of creep strength loss can explain the discrepancy between the strength measured in the laboratory and that modified at failure in the field. Empirical corrections for measured strength are recommended

Journal ArticleDOI
TL;DR: In this article, three-dimensional finite element analyses were performed for dams in valleys with valley wall slopes of 1:1, 3:1 and 6:1 to evaluate the accuracy of two-dimensional analyses.
Abstract: Three-dimensional finite element analyses were performed for dams in valleys with valley wall slopes of 1:1, 3:1, and 6:1. The results were compared with the results of two-dimensional analyses to evaluate the accuracy of two-dimensional analyses. The conclusions were: (1) plane strain analyses of the maximum transverse section provide accurate results for dams in valleys with valley wall slopes 3:1 or flatter; (2) plane stress analyses of the maximum longitudinal section do not provide accurate results; and (3) plane strain analyses of the maximum longitudinal section provide fairly accurate results for all valley wall slopes.

Journal ArticleDOI
TL;DR: In this article, a method was developed for the analysis of seepage through nonhomogeneous soil deposits, where the layers of pervious soils in the deposit were considered as inclusions within a medium of much lower permeability.
Abstract: A method was developed for the analysis of seepage through nonhomogeneous soil deposits. The layers of pervious soils in the deposit were considered as inclusions within a medium of much lower permeability. The locations and dimensions of the inclusions were assumed to be random variables. Field studies of excavations provided the basis for the statistical representation of the inclusions. Data obtained from the Mississippi River alluvium and fluvial glacial deposits were interpreted by means of the statistical model. The results were used to compute the seepage at the Port Allen Lock excavation and the Granville Dam. The computed seepage is of the right order of magnitude when compared with the measured seepage.

Journal ArticleDOI
TL;DR: In this paper, the undrained strength and stress path of a soft marine clay subjected to different periods of secondary consolidation under isotropic stress was examined, and the effect of the pore-water pressure buildup was shown to produce steeper undrained stress paths at small strains only.
Abstract: The undrained strength and stress path of a soft marine clay subjected to different periods of secondary consolidation under isotropic stress was examined. The phenomenon of buildup of pore-water pressure has been shown to be due to the arresting of secondary compression. The effect of this phenomenon on the undrained strength and stress path was also studied. The results have been explained using the Cam-clay model. It is concluded that secondary compression would cause increase in undrained strength and stiffening of the stress-strain characteristics of bay mud, while the effect of the pore-water pressure buildup was to produce steeper undrained stress paths at small strains only.

Journal ArticleDOI
TL;DR: In this article, the authors investigate the impact of RIGID PROJECTILES into KAOLIN CLAY TARGETs with CAthis articleULLY CONTROLLED PROPERTIES.
Abstract: PENETRATION OF RIGID PROJECTILES INTO COMPACTED KAOLIN CLAY TARGETS WITH CAREFULLY CONTROLLED PROPERTIES IS INVESTIGATED. A EXAMINATION OF THE EXPERIMENTAL TECHNIQUES FOR MEASURING THE SOIL RESISTANCE TO A PENETRATING PROJECTILE IS PRESENTED. PROCEDURES FOR CONSTRUCTION OF TARGETS AND DETERMINATION OF SOIL PROPERTIES IS DESCRIBED. PROJECTILE DIAMETER IS VARIED FROM 1.5 IN. TO 3 IN. (40 MM TO 75 MM) AND PROJECTILE WEIGHT IS VARIED FROM 3 LB F TO 115 LB F (10 N TO 510 N). SIX DIFFERENT NOSE SHAPES ARE TESTED. IMPACT VELOCITY IS VARIED FROM 30 FPS TO 300 FPS (9.0 M/S TO 90 M/S). THE EFFECT OF PROJECTILE AND SOIL PROPERTIES ON THE DECLERATION HISTORY OF THE PROJECTILE IS DEMONSTRATED. TEST RESULTS INDICATE THAT A CRITICAL VELOCITY EXISTS ABOVE WHICH SEPARATION OF THE SOIL OCCURS DURING PENETRATION. THE CRITICAL VELOCITY IS A FUNCTION OF BOTH SOIL AND PROJECTILE PROPERTIES. /AUTHOR/

Journal ArticleDOI
TL;DR: In this article, different degrees of anisotropy were induced in two kaolinitic clays and one illitic clay by one-dimensional consolidation of thin hollow circular cylinders in a specially designed cell.
Abstract: Different degrees of anisotropy were induced in two kaolinitic clays and one illitic clay by one-dimensional consolidation of thin hollow circular cylinders in a specially designed cell. For each degree of anisotropy, a pneumatic analog computer was used to subject the clay specimens to 16 different stress paths corresponding to a wide range of inclinations of the principal stresses on the axis of symmetry of the material. The computer was programmed to maintain this inclination constant for the duration of each test. The results show that the incremental strain-stress relations which are presented are valid for the three clays at their various degrees of anisotropy. The failure criterion of Goldenblat and Kopnov which takes into account anisotropy as well as the difference in behavior between extension and compression, is found to be extremely satisfactory in the range of stresses covered.

Journal ArticleDOI
TL;DR: The phenomenon of liquefaction was investigated by comparing field evidence of an actual landslide with laboratory testing and analysis as discussed by the authors, and the landslide occurred during the February 9, 1971 San Fernando earthquake at the site of a nearly completed water filtration plant in southern California.
Abstract: The phenomenon of liquefaction is investigated by comparing field evidence of an actual landslide with laboratory testing and analysis The landslide occurred during the February 9, 1971 San Fernando earthquake at the site of a nearly completed water filtration plant in southern California The cause of the landsliding was liquefaction of a natural deposit of saturated alluvium underlying a thick interval of compacted fill Analytical and laboratory testing procedures are presented that demonstrate the validity of evaluating liquefaction potential during an earthquake

Journal ArticleDOI
TL;DR: In this paper, the performance of earth retaining structures is analyzed to illustrate certain weaknesses in the conventional design practice, and it is shown that the yielding of a retaining structure by an amount required for the earth pressure to drop to the minimum active state does not necessarily provide assurance that active earth pressure will prevail for more than a limited period of time.
Abstract: The performance of earth retaining structures is analyzed to illustrate certain weaknesses in the conventional design practice. It is shown that the yielding of a retaining structure by an amount required for the earth pressure to drop to the minimum active state does not necessarily provide assurance that active earth pressure will prevail for more than a limited period of time. If a design is based on the active earth pressure, while the actual earth pressure may at times be equal to or greater than the earth pressure at rest, the actual factor of safety would be close to unity. It is demonstrated that anchored bulkheads are particularly vulnerable in this respect because the design of a competent anchorage may require an assumption of forces at the anchor level that are equal to two to three times those computed on the basis of a conventional design using active earth pressure.