In order to apply the iron and steelmaking slag to improvement of the seismic safety of the pile foundation, it is necessary to understand the physical and mechanical properties quantitatively. Hence the fundamental experiments including expansion test, permeability test and tri-axial compression test were carried out on the slag-specimens with several curing period. In application to the actual pile foundations, there is great concern that the swelling of the slag would affect on pile caps. Thus, the authors performed the slag swelling tests with new device designed for measuring expansion-stress of slag. This paper presents the test results and discussions about them.

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Our research consists of two types of frost heave test. One test uses undisturbed rock samples. The other uses artificially-shattered rock samples, which have no tensile strength. Using frost heave test equipment made in the laboratory, we conducted frost heave tests on undisturbed samples. The Ohya tuff and Kimachi sandstone were classified into frost susceptible while the Sapporo soft rock was classified into anti-frost susceptible. To determine the factors behind these results, we compared the physical characteristics of frost susceptible rock and anti-frost susceptible rock. These measurements clarified certain differences in the physical characteristics between frost susceptible rock and anti-frost susceptible rock. We also conducted frost heave tests on artificially-shattered rock samples to investigate the effect of shattering, using test equipment made in the laboratory. In these tests we employed the test method established by the Japanese Geometrical Society for determining the frost susceptibility of soil. The results indicate that the frost susceptibility of rock is amplified by shattering. Furthermore, it was also clarified that shattering brings a heaving tendency even to anti-frost susceptible rock.

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It has been proved in the engineering practice that vacuum consolidation method gives remarkable effect on improving soft soil ground from the view points of accelerated consolidation and increase in strength. The purpose of this study is to establish the predicting method of deformation behavior of peaty soft ground under embankment loading followed by vacuum consolidation. So far, it has been considered very difficult to estimate even the final settlement of peaty soft ground, and regarded as almost impossible to estimate the rate of settlement by using oedometer test results. It is considered that the difficulty of performing settlement analysis for peat soil based on Terzaghi theory is due to the stress dependency of coefficient of consolidation c_v and the development of large shear deformation under the embankment loading. In this paper, the authors point out that deformation analysis with practically sufficient precision can be performed by using soil-water coupled elasto-plastic FEM which is able to consider the effects of stress dependency of c_v and development of shear deformation on the consolidation process of peaty soft ground.

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Takamatuzuka Tumulus, having found in 1972 at Hirata, Asuka village in Nara Prefecture was built with mural paintings in the stone chamber around at the end of 7^th century or at the beginning of 8^th century. Because various fungi has recently appeared on the lime plaster wall on which the precious paintings are drawn together with intrusion of insects into the stone chamber, which seriously has damaged wall paintings, it is very urgent to restore and conserve them with the relevant measures. In the present paper, the record of temperature, humidity inside the chamber with connection to atmospheric temperature is shown. The record of moisture content by volume on the surface of the lime plaster wall is also shown to understand the environment of the stone chamber. Sampling of the mound soils and various sounding tests were carried out to know the present condition of the mound. Density of Hanchiku, made up by compaction method exhibits the sinusoidal shape and moisture content of the mound varies around 15 to 25% in average irrespective of the location. The equivalent unconfined compression stress of Hanchiku is found to be 200 to 1000kN/m² with the shear wave velocity of 70 to 160m/s.

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In this study, the relationships between the angle of internal friction, void ratio, and particle shape are presented for six kinds of sand, in which the particle components mainly comprise silica (SiO₂) or calcium carbonate (CaCO₃) and the particle size is uniform. The coefficient of form unevenness FU proposed by Yoshimura and Ogawa is employed to quantify the particle shape. It is indicated that not only particle shape but also hardness and surface roughness of the sand particles affect void ratio, angle of internal friction and dilatancy. Further, the relation figure between the parameter k of Mogami's expression and FU is presented. It is proposed that the angles of internal friction of sands with an arbitrary density at peak are estimated by using FU.

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