SLOPE FAILURE OF EMBANKMENT IN SANYO EXPRESSWAY DUE TO PASSAGE OF TYPHOON NO. 14 IN 2005

Abstract

Typhoon No. 14 in 2005 caused significant rainfall in Yamaguchi Prefecture of Japan, and, due to this, an embankment of Sanyo Expressway at Hataki in Iwakuni city failed. Detailed investigation was conducted after this event in order to identify the mechanism of this failure, which consisted of the field studies as well as laboratory tests and numerical analyses. It was consequently shown that the combined effects of heavy rainfall and the local geological and topographic conditions as well as the reduction of drainage capability due to the breakage of perforated pipe in the underdrainage system were the causes of the failure.