An analysis is proposed for determining the static and kinematic characteristic lines for a medium of anisotropic cohesive clays. It is proved that, similar to the isotropic case, the velocity field and the stress field coincide and their lines intersect at an angle of π/2. The compatibility equations along the slip lines are derived. An adopted strength function containing four degrees of freedom has proved to be in very satisactory agreement with laboratory tests. The above derivation is applied to determination of the bearing capacity. It is shown that for a considerable amount of anisotropy, a misleading evaluation of the bearing capacity may be reached if the anisotropic phenomenon is disregarded.

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On the confirmed knowledges in regard to the fabric characters of granular material and their reconstructions during the compressional deformation, its mechanical and statistical model is proposed. The mean value of force acting on a contact is determined as a function of the state of principal stresses and the inclination angles of the normal to the principal stress axes. The relation between the mobilized principal stress ratio and the fabric index of granular material is determined by the consideration on the static equilibrium of forces at the contact. The probability of sliding at a contact can be calculated by considering that the forces at the contact are random variables having their mean values and standard deviations. The rates of strain in the principal directions are theoretically obtained in terms of the frequency and intensity of sliding and the fabric characters, and then the relations between the fabric character, the dilatancy index and the mobilized stress ratio are proposed. The relation between the void ratio and the distribution character of the normal which must be satisfied at the peak stress state is also discussed. The theoretical equations accord well with the experimental results by means of the microscope and thin section method.

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The shear mechanism of granular materials has been studied from the microscopic point of view in order to analyze the basic macroscopic stress-strain relationship of soil. For this purpose, special direct shear tests were performed by using cylindrical rods of aluminum and of a photoelastic substance as two-dimensional models of soil. By introducing the concept of the frequency distribution of the angles "θ" of interparticle contact on the potential sliding plane (mobilized plane) and its variation during shear, and by evaluating the transmission of interparticle force "f" and the angle "φ_μ" of interparticle friction on the same plane, the relationship between the shear resistance (τ/σ_N : shear-normal stress ratio) and dilatancy rate (dε_N/dγ : normal-shear strain increment ratio), the relationship between the shear resistance(τ/σ_N) and dilatancy(ε_N : normal strain) on the mobilized plane, and the like have been derived from the microscopic analysis of the behavior of grains under shear. Based on the measured data of the change of the frequency distribution of θ during shear and the foregoing basic stress-strain relationships, the origin of the stress-strain curve of soil has been clearly explained.

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A theoretical analysis was performed on the lateral behavior of double sheet pile wall structures. The analysis considers an elastic equilibrium of forces acting on a horizontal slice cut from the over-all structure to introduce the basic equations on the deflection of sheet piles. Then these equations were solved for the six cases of simple boundary conditions. Of all the solutions thus obtained two cases were compared with experimental results. The agreement was found out to be fairly satisfactory except that some measured values have appeared much higher.

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A half-space of elastic material, the Young's modulus of which increases linearly with depth, has been shown, as the degree of inhomogeneity increases, to respond to surface loading more as predicted by Winkler's subgrade reaction theory and less like a homogeneous isotropic elastic material. The present paper discusses the relationships between degree of inhomogeneity and Poisson's ratio and the corresponding bending moments and displacements in rafts. Detailed consideration is given to the variation of maximum bending moment in a uniformly loaded circular raft of any flexibility, variation of differential displacement in a uniformly loaded very flexible circular raft, and displacement of a rigid raft.

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The applicability of the split tensile test for the measurement of the tensile strength of cohesive soils is discussed. The results of unconfined compression tests and split tensile tests on cohesive soils compacted dry of optimum are presented. It is shown that the split tensile test is a simple and reliable method of measuring the tensile strength of cohesive soils compacted dry of optimum. From the test results, it is also observed that the ratio of the unconfined compressive strength to the split tensile strength is nearly a constant for the soils tested.

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