Journal of Natural Disaster Science

Mechanism of Earthquake-induced Landslides on almost Flat Slopes Studied with a Ring Shear Apparatus

Dmitri A. Vankov
Graduate student, Landslide section, DPRI, Kyoto University, Japan
and
Kyoji Sassa
Professor, Landslide section, DPRI, Kyoto University, Japan

(Received 22 June, 1999 and in revised form 18 October, 1999)

Abstract

A series of undrained ring shear tests were made on coarse grain sandy soil to simulate stress conditions in a landslide on an almost flat slope during an earthquake. Test results indicated that pore pressure was generated in the shear zone and that the soil was likely to liquefy. The mechanism in this process, however, is speculated to difler from that of conventional liquefaction, because liquefaction phenomena still was present in the dense state. In addition, frequency of loading influenced the total dissipated energy required for liquefaction. The possible mechanism for a landslide on a flat slope is proposed. The reliability and suitability of the ring shear apparatus for reproducing stress conditions on a potential sliding surface was proved.

Key words

landslide, ring shear test, cyclic loading