The passive progressive failure in a mixed boundary value problem of a retaining wall rotating about its toe, rotating about its top and translating into a dry sand medium is studied. The analyses developed in this work aided by the proposed computational procedures would provide a more reliable means of predicting the load-deformation characteristics at all working loads, rather than only loads at failure, in practical retaining wall problems.The stress-strain data are compared with corresponding values obtained from the conventional analysis which bases the solution of the earth pressure problem on the soil properties at the state of failure, and marked differences are noticed.

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The present paper deals with the micro-structure of a kaolin clay compacted in accordance with JIS A 1210. The methods used for investigation are the scanning electron microscopy using samples impregnated with polyethylene glycol, the X-ray diffraction, and the permeability test method. From this series of experiments, it is recognized that the micro-structure of the compacted kaolin clay mainly consists of block structures which are almost independent of the inner particle arrangement and are of the three-dimensional structure. The two-dimensional feature, therefore, varies depending upon the direction and position to be observed. It is also recognized that the parallelism as a soil mass increases more or less according to the molding moisture content as indicated by the results of X-ray analysis and k₀S² from the Kozeny-Carman equation, and the change of this parallelism may be caused not by the change of each particle arrangement but by flattening and/or deforming of block structures.

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Boussinesq's and Cerruti's equations for point loads are combined to obtain an equation for point load inclined at an angle to the vertical. This has been extended to include inclined linear loads also. Cerruti's equation for horizontal point load has been integrated over a rectangular area and the influence value is presented in the form of a chart. Stress bulbs for various inclination of the loads are also presented in the paper.

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By taking into account the geological processes of formation of alluvial and diluvial soil deposits, it has been found that the soil deposits are classified into six major types in urban areas in Japan situated on alluvial plains. The same result has been reached by applying a computer technique, which has been developed to simplify an original, complicated boring record in the form of a refined soil profile, to the numerous boring data obtained in city areas which consist of a wide variety of soil conditions. Statistics on thicknesses and N-values are also given for sublayers of soil deposits belonging to each major type and, furthermore, the ranges of predominant periods for strain levels of microtremors and strong-motion earthquakes are evaluated with respect to each type of soil deposits.

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After a subsurface layer of soil is liquefied completely, the excess pore water pressure therein is dissipated through the overlying layer of soil. The Terzaghi consolidation theory is applied to the problem to determine the excess pore water pressure, and numerical solutions are obtained using the finite element method for a variety of initial and boundary conditions. If the compressibility of the surface soil is one order of magnitude smaller than that of the initially liquefied soil, the maximum pore pressure in the surface soil is not significantly affected by the initial excess pore pressure in the surface soil, the relative thickness of the surface soil with respect to the initially liquefied soil, the drainage condition at the lower boundary of the initially liquefied soil, or by the depth of the water table. The smaller the permeability and compressibility of the surface soil, the smaller becomes the shear strength of the soil due to the upward seepage. The surface soil can even be liquefied if its permeability and compressibility are sufficiently low as compared to those of the initially liquefied soil.

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This paper deals with elastic surface settlement of a cross anisotropic medium due to a point load and axi-symmetric distributed load. Out of five elastic constants, viz., two Young's modulii, two Poisson's ratios and one shear modulus, characterising a cross anisotropic medium, it has been possible to eliminate one Poisson's ratio. Graphs have been presented taking into account the other elastic constants, and from these graphs the elastic settlement for a moderately anisotropic medium can readily be calculated.

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[in Japanese]

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