Abstract
Kanto loam mainly consists of allophane clay mineral. Geologically, Kanto loam is distributed in the order of Tachikawa loam and Musashino loam from earth surface. Tachikawa loam is the newest stratum and its allophane content exceeds 50%. Whereas, the allophane content of Musashino loam is less than 40%. Kanto loam has very high water content and high sensitivity caused by containing allophane clay mineral. Therefore, the most effective stabilization of Kanto loam is chemical one such as quick lime stabilization. The equation of dehydration of quick lime cannot apply to Kanto loam, because allophane in Kanto loam must have influence on it. Lime stabilized soil is high alkaline, and then the leached water through the soil becomes high alkaline. As the buffer ability for acid and alkaline solution increases with increasing allophane content, Tachikawa loam has higher buffer ability. On the other hand, Musashino loam can be expected to increase the strength by adding quick lime. Thus, the embankment considering the environment can be designed by using geological formation of Kanto loam, such that Musashino loam is used for the embankment material and Tachikawa loam is used for the buffer material. The result of this study shows that the thickness of the buffer material is related to the thickness of the embankment material and the rate of allophane content of both materials.
