ABSTRACT
Many landslides have occurred due to slope cutting and soil excavation for tunneling during road construction along the Median Tectonic Line in Shikoku region. There are two geological belts namely, Izumi and Sambagawa along this tectonic line. The mother rocks of Izumi belt are sandstone and shale, and those of Sambagawa belt are green and black schists. To apply suitable countermeasure works, it is necessary to have a clear idea on general landslide characteristics. Therefore, in this paper, the general characteristics of landslides caused by road construction works were investigated, and the same were compared to those of the spontaneous landslides. The angles of peak shearing resistance of landslide clay from Izumi belt were found to be larger than those of landslide clay from Sanbagawa belt, and the angle of residual shearing resistance of clay from latter belt was found to be very small.
