The considered section where was between two faults of the decomposed granite expanded upward. The section was the dark gray decomposed granite that mainly consisted of biotite. The outer side of two faults was the white decomposed granite that mainly composed of quartz and feldspar. The direction of a relative expansion of the portion pinched between two faults was about 51-degree slant upper part, and the amount of displacement was a maximum of about 26 mm. For the predictions, the elasto-plastic FE analysis based displacement control was con-ducted. The relative displacement obtained by FE analysis was almost agree with the actual relative displacement. X-ray diffraction was performed on two kinds of decomposed granites. The kaolinite and mica were contained rich in the dark gray decomposed granite. The quartz, potassium feldspar and plagioclase were contained rich in the white decomposed granite. The kaolinite and mica in the dark gray decomposed granite were a weak combination of minerals. For this rea-son, it was found that the larger expansion may be caused by cutting. On the other hand, as the quartz was a stable mineral, no expansion may be appeared, and the white de-composed granite was a less amount of expansion induced by cutting.
It is very important to develop new techniques for soil sterilization because the use of methyl bromide, which had been widely used all over the world, was banned in 2005 in Japan. Using hot water for soil sterilization has become popular in Japan as an alternative for methyl bro-mide. However, because using hot water is relatively new, few studies have been conducted. In this study, we inves-tigated solute dynamics by measuring temporal changes in the concentration of chloride, nitrate, nitrite, and ammo-nium ions in soil. Hot water with the temperature of 90 ◦C was applied to the soil surface at the rate of 204 L m−2 dur-ing the experiment. Soil samples were manually collected for analyzing solute concentration in triplicates between the soil surface and 40 cm deep with a 5 cm interval just before starting, 9 days after, and 3 months after the hot-water application. As the result of the experiment, leach-ing with high temperature was found to be more hastened than that with normal temperature. We found that solute concentrations increased between 30 cm and 40 cm deep by solute diffusion from a deeper portion in 3 months after the hot-water application. On the other hand, applying hot water suppressed the form change at first because nitrify-ing bacteria was killed by the hot water in soil. However, ammonium nitrate decreased with time in deep layers by nitrifying bacteria restored from a deeper layer.