A series of hollow cylindrical torsional shear tests have been carried out to investigate the influence of excess pore-water pressure generating at preshearing on the liquefaction resistance of saturated sand. Consequently, the liquefaction resistance of saturated sand was cleared to be affected by three factors, pre-shear strain (effective shear stress ratio), excess pore-water pressure (effective stress condition) at preshearing, and the number of cycles. And the increase of liquefaction resistance was confirmed to be achieved by restraining the excess pore-water pressure.

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The effects of secondary injection during shield work on the prevention of ground subsidence were examined, using the measurement results of ground displacement during shield work in soft clayey ground. In order to investigate the deformation of soft ground during shield work, the finite element analyses were carried out by taking account of the consolidation of soft clayey soil due to the disturbance of micro-structure of soil. In case of soft clayey soil, the secondary injection could become the cause of ground subsidence because of the disturbance of micro-structure of soil associated with the fracturing phenomena during secondary injection. The guidelines for the design and execution procedures of secondary injection in soft clayey ground were also proposed.

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In this paper, the groundwater behaviour under Lugeon's test in hydraulic anisotropic rock masses is theoretically explained. To derive the solution of seepage phenomenon induced by Lugeon's test, the boundary condition along packed off interval is idealized as line source, and another boundary condition at infinite is zero potential. The potential increment at the center of injection interval on the wall of bore-hole was calculated by solving the potential flow equation. Lugeon's values which is theoretically evaluated for various anisotropic porous media agree with the true values and the calculated ones by the three-dimensional finite element analysis. A method to determine the three-dimensional hydraulic conductivity tensor for fractured rock masses is proposed from these researches.

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A series of test pilings was performed with open-ended steel pipe piles driven in a soft rock named diatomaceous mud stone. The test pilings were consisted of dynamic load testing including initial driving and redriving as well as static load testing of the three test piles and a large-scale rigid plate, aiming at gathering reliable data for set-up behavior and bearing mechanism of open-ended piles in this particular soft rock. The ground around the test piles was instrument with piezometers and an accelerometer. Intensive in-situ soil investigations and laboratory soil tests were conducted prior to pile installation. They were also performed after the end of static loading tests. In the earlier part of this paper, the results of the test pilings are presented and discussed. Then, the test results are compared with the ultimate bearing capacities estimated from several specifications available in Japan, in view of role of in-situ investigations and soil tests in design of pile foundations in this particular soft rock.

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The numerical procedure using crack tensors has been performed with the assumption that the normal and shear stiffnesses of joints are equivalent. In the present study, their stiffnesses were determined according to the experimental observation, the normal stiffness is larger than the shear stiffness, by Bandis et al. (1983). To investigate the influence of the geometry of joints and the three-dimensional excavated shape on the stress and deformation around the intersection of tunnels and compare with results of field measurements at the intersection of tunnels, three-dimensional finite element analysis modelling the in-situ jointed rock mass by crack tensors has been carried out, with the following conclusion: The numerical procedure newly taking into account the anisotropy of normal and shear stiffnesses in joints makes it possible to predict the behaviour of jointed rock mass more accurately than the conventional one.

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A new method to determine quantitatively the roughness of rock joint is proposed. Considering rock joint roughness, which is expressed in the relation of asperity vs. shear displacement, as a series of waves in the amplitude vs. time relation, wave forms corresponding to various roughnesses were analyzed in terms of power spectra by FFT (Fast Fourier Transform) and MEM (Maximum Entropy Method). It is concluded that a value of Power Spectrum Moment (M_s) defined by MEM can be uniquely determined for rock joint roughness with high resolvability, and it owns high applicability to practical use. The validity of this M_s-method was verified through the experiment on several natural joints, which were analyzed by our newly-developed 3-D profiler, in comparison with Barton's JRC-values.

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The thermal expansions of three granitic rocks and two andesites have been measured at confining pressures of 0, 9.8, 29.4, and 49.0MPa and at temperature from 30 to 284°C by use of a new apparatus. The observed thermal expansions of these rocks are dependent of both temperature and pressure. Significant differences in the thermal expansion behavior exist between granitic rock and andesite. The results indicate that the thermal expansion behavior of igneous rock can be determined by the four factors: the thermal expansion of constituent minerals; the phase transition of constituent minerals; microcrack formation and extension induced by thermoelastic property differences between adjacent grains; and pore volume decreases related to thermal compaction.

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The objective of this paper is to develop a simulation analytical method which is able to predict the amount of sinkage, the turning radius, and the drawbar pull of a tracked vehicle during turning motion. This simulation analytical method is useful for the design and the development of a tracked vehicle.
As a result, it is clarified that the simulation analytical method is verified to be useful for predicting several land locomotion performances of the tracked vehicle under turning motion.

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The purpose of this paper is to study the fundamental characteristics of inherent amsotropic Toyoura sand under drained cyclic shear conditions. Towards this end, cyclic loading tests and a loading test with rotation of principal stress axes were carried out using a large hollow cylindrical apparatus. Through the analysis of the experiment results, it is verified that the drained cyclic shear behavior of sand with inherent anisotropy could well be simulated, using the concept of a field of hardening moduli on the deviatoric stress plane and a function of normalized plastic work, based on the characteristics regarding drained shear behavior under monotonic loading.

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Model test result for tunnel-ground interaction and consideration of designing models applicability using the result are discussed. Some design models are evaluated for the interaction by the model test result. Since any evaluated models have sufficient safety on shield tunnel design, conventional design model in Japan has a little rationality.

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Soft rock materials are frequently used for fills and subgrade in construction works. However, the stability and the durability of such materials is generally poor under natural environments. In this paper, the influence of rock properties and compaction degree on the mechanical stability of the compacted materials is investigated. First, the properties of soft rocks are inspected by being associated with their use for fill materials. Next, the settlement and the strength reduction of compacted materials due to slaking and grain breakage of rocks are examined through some laboratory experiments. As a result, it can be found that there exists a specified relationship among the properties, the compaction degree and the mechanical stability of compacted soft rock materials.

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A simplified method has been developed to design landslide stabilizing piles in multiple rows as well as in a single row in terms of the limit equilibrium approach. The entire design procedure of the landslide stabilizing piles consists of three stages, i. e. evaluating the deterrent force. calculating the lateral bearing capacity, and designing the piles themselves. In this paper, theories relating to the first two stages have been discussed. Combining the concepts on the deterrent force and lateral bearing capacity yields a criterion for the selection of the desirable pile location. As a result, it has turned out that we can determine the optimal value for the ratio d/D₁, at any place under a prescribed, objective factor of safety, where d is the pile diameter and D₁ is the center-to-center distance of the piles.

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Dispersion coefficient was evaluated from laboratory measurements of solute transport through vertical sand column being applied air vacuum at the bottom. This study concluded that the applied vacuum is useful method to maintain the water saturation at a constant value throughout the column, and dispertion coefficient tends to increase with decreasing of water saturation.

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A Eulerian-Lagurangian numerical method is very useful for groundwater flow with mass transport analysis. In this study, we improved the method for two-dimensional saturated-unsaturated flow in consideration of density dependent characteristic. Validity of this method was proved in comparison with the theorical solutions and the experimental results. Also, this paper show that the method enable to simulate precisely groundwater flow with mass transport without dependence on mesh size.

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This paper deals with a proposal of a simulation material (SM) for naturally cemented sensitive clays and its compression and shear deformation behavior. The SM is obtained from simulating the process of natural sedimentary environment by controling the ratio between increment rate of soil density and increment rate of cementation. A series of constant strain rate of consolidation, undrained triaxial compression and cyclic undrained torsional simple shear with constant strain amplitude and variable strain rate (VSRA) tests was carried out for SM. The results showed that (1) the compressibility and undrained shear behavior of SM are similar to naturally cemented sensitive clays, (2) at VSRA test, the effect of strain rate of SM is not dominant.

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The current design method for anchoring capacity of HDPE geomembrane used for liner in a waste landfill considers its strength and do not its deformation. In this paper, a simple elastic formula which relates a deformation with the pull-out force is proposed. Model tests were also conducted in order to verify this proposed formula. As a result, it is found that deformation is directly proportional to a square of pull-out force per unit width and is inversely proportional to a elastic modulus of geomembrane, a weight of cover-soil as well as a frictional coefficient between soil and geomembrane and that the caluculations based on this elastic formula coincided well with the experimental observations.

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The authors investigated the disturbance and backfilling in the area surrounding a segment through grout holes at 40sites. The analytical results of the measured data show that the disturbed area consists of a cavity in which the tail void remains, and a collapsed region caused by over excavation and meandering. In addition, a computational expression for rational amount of backfill grouting according to ground type and strength considering the magnitude of the disturbance is proposed.

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This paper describes on the mechanical properties of light-weight soil which were improved cement and foam. Especially, the influence of foam volume ratio on shearing strength in light-weight soil is studied.
As result of these studies, it is clear that the influences of foam volume ratio on shearing strength are affected at axial strain above 5% and high volimetric strain are occured with increment of foam volume ratio. And the failure criteria of light-weight soil is not only indicated the relation q and p′ but also is indicated by consideration of volumetric strain, and it is different by the magnitude foam volume ratio.

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A basic framework is proposed for the constitutive modeling of frictional materials. The theory has capability to reflect dissipation mechanism in terms of the dissipation condition, which is a generalization of the yielding condition. The dissipative strain-rate in this theory consists of two parts; the primary and subordinate strain-rates. The subordinate strain-rate, a generalized form of instantaneous dilatancy, is related anisotropically to the primary strain-rate, while the total strain-rate is determined with an energetically-derived flow rule as well as the associated consistency condition. Through examples, it is shown that the frictional dissipation condition leads to a reasonable constitutive law for granular materials.

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The mechanism of fabric changes which controls shear behavior of granular materials was investigated numerically at microscopic level by DEM. For that purpose, several biaxial compression tests on granular assemblies were simulated. Based on the mechanism of fabric changes, a method called “predictive method for particle movement” was proposed. The new method predicts fabric changes and stress-strain relations under shear using the geometrical data for the particles at initial hydrostatic stress condition. Fabric changes and stress-strain relations by the newly proposed method were compared with the numerical results obtained by DEM. The investigation made clear that the method properly takes account of the main mechanism of fabric changes and can accurately predict the stress-strain relation for granular materials.

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In this study the mechanical properties of unsaturated light-weight soil were investigated. Laboratory test regarding initial suction, isotropic consolidation, consolidated drained and constant water tests were performed.
It was learned that initial suction didn't exist and collapse phenomena don't occur when the isotropic stress is below consolidated yeild stress. As a result it was found that the stress path, volumetric change and the fialure criterion of this peculiar unsaturated light-weight soil should be described with a indipendent effective strength formula.

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In order to investigate the effects of principal stress directions on undrained and drained shear behaviour of inherent anisotropic sand, a series of strain controlled undrained shear tests and stress controlled drained shear tests for airpluviated two kinds of sand has been carried out under fixed principal stress directions using hollow cylinder torsional shear apparatus. As a result, it was found that, in spite of the drain and undrained condition, the deformation and strength characteristics of two sands was characterized by the smaller angle of between the bedding plane and the planes of maximum stress obliquity.

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We have carried out an experiment in which heaps of garanular materials are built up to a certain size by dropping of particles on the table from the hopper. During the failure of the surface of the slope by the flow of particles and after the relaxation of the pile, the slope angle and the crest point of the heaps are measured. Varying the dropping point of the paritcles on the table, we find some interesting relationships in the deviation of the crest point of each heap which corresponds to the slope of failure surface.

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This paper describes the influence of test conditions on volume change characteristics of unsaturated soils after soaking. Two types of commercially available soils refered to as DL clay and Kaolin were used in this series of experiments. The specimens were then statically compacted up to the required height corresponding to a specified dry density. The test program consisting of the single-oedometer and double-oedometer tests were performed for the two kinds of soils. It is also investigated the influence of some important factors such as the initial degree of saturation, the initial dry density and the applied pressure on the amount of collapse of unsaturated soils after soaking in this paper.

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