The Note presents results of an investigation on two principal types of a residual soil (saprolite) derived from migmatite, encountered on a 30 m high cut in Rio de Janeiro. The main difference in mineralogy between the two soil types lies in the proportion of biotite and alkaline feldspar. A large number of drained shear tests were carried out to compare the shear strength of compacted and undisturbed samples in both partially saturated (unsoaked tests) and saturated conditions. Unlike the type A soil consisting essentially of quartz and feldspar, the type B micaceous soil shows a distinct difference in shear strength in the compacted and undisturbed states. A number of characterization tests performed to evaluate the variation of physical properties along the weathering profile show a decrease in particle size and specific unit weight of soil grains with weathering.

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Graphical results are presented for load taken by piles, maximum displacement and differential displacement, and maximum positive and negative bending moments, due to uniformly distributed loading applied to a smooth strip footing which is supported by piles and a very deep homogeneous isotropic elastic foundation.The results presented are for piles whose length/diameter ratio is 50, footings whose width is 5 pile diameters and an incompressible foundation. Corrections for other pile length/diameter ratios, other footing widths and soil Poisson's ratio of zero, are discussed.

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The effect of water on the mechanical properties of a quartz-rich sand is investigated by using the results obtained from high pressure triaxial tests on the sand in both dry and saturated states. It is shown that water increases the compressibility and decreases the shear strength of the sand under high pressures, and that these phenomena have a close relation with the activation of particle-crushing in the presence of water. The mechanism of the water action on the lowering of particle strength is investigated from a mechano-chemical viewpoint, and it is concluded that the water sensitivity of the sand is probably due to the surface energy change of cracks which would be produced in each particle under high stresses.

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Oda and Konishi (1974 a and b) obtained the following relation between the stress ratio τ/σ_N on the apparent shear plane and the inclination angle ψ of the maximum principal stress axis in the simple shear test on the granular material : τ/(σ_N)=κ·tanψ In this paper the physical meaning of the constant κ is made clear. The constant κ has the same physical meaning as the frictional constant which has been defined as the ratio of the shear stress to the mean normal stress at the critical void ratio state by Roscoe, et al. (1958). It can be also formulated in a simple form with the other important soil parameters such as the internal friction angle at the critical void ratio state and the earth pressure coefficient at rest.

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The growth mechanism of lateral force acting on stabilizing piles in a row due to the surrounding ground undergoing plastic deformation is discussed, and its theoretical analysis is carried out considering the interval between the piles. In this analysis, it is assumed that two types of plastic states occur in the ground just around piles, one of which is a plastic state satisfying Mohr-Coulomb's yield criterion and the other a plastic state where the soil is considered as a visco-plastic solid. The former is called the theory of plastic deformation and the latter the theory of plastic flow. Then, the characteristics of both theoretical equations are clarified by examining the effects of various parameters on the lateral force. Comparing between the theoretical and the observed lateral forces which are obtained in the stabilizing piles against landslides, the order of magnitude of the theoretical values due to both theories agrees with that of the observed values. Whereas, the theoretical values due to the Hennes' equation underestimate and the equation of the Public Works Research Institute overestimate the observed lateral force. Especially, it is clarified that under the condition of restrained pile top, the lateral force acting on stabilizing piles may be estimated by the theory of plastic deformation.

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Anisotropically consolidated natural deposits of clay show the stress-strain responses in different ways for the cases of active and passive loadings. This is caused by the anisotropy in initial stress states of normally consolidated or overconsolidated clays. Incremental stress-strain relations of anisotropically preconsolidated clays are derived from their consolidation and dilatancy characteristics with the help of associated flow rule. Obtained stress-strain relations give reasonable explanations to the anisotropy in mechanical behaviour of anisotropically preconsolidated clays. Integrations of the incremental stress-strain relations give the stress-strain relations under specified loading conditions or some restrictions on the deformation of clay.The finite element analysis may be one of the powerful means to analyse the stress and strain fields in clay layers consolidated anisotropically in which there exist two different patterns of stress-strain response due to the loading systems, active and passive. As an example, the stress and strain fields in normally and anisotropically consolidated clay layers stressed by a uniform strip load are computed with the finite element technique using the above mentioned anisotropic stress-strain relations.

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To correlate the actual liquefaction phenomena and site conditions, a literature survey about liquefaction phenomena brought by earthquakes during the last century in Japan was performed. Liquefaction distribution map of Japan and the regional maps of Kanto. Nobi and Hokuriku are presented and the factors in relation with liquefaction are discussed. In the last century liquefaction in subsoils has been observed at some hundred sites in at least 44 earthquakes and the sites were limited only to alluvial deposits and reclaimed lands. Furthermore, it was found that liquefaction occurred repeatedly in different earthquakes in several zones. Estimated JMA intensity scale at liquefied sites were more than the fifth grade which means maximum acceleration of 80 to 250 gals. The extent of liquefied zones are limited depending on the magnitude of the earthquakes.

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