A case study on rainfall infiltration effect on the stability of two slopes

摘要

Two landslides occurred in Malaysia after a heavy rainfall period in 1999. An investigationconsisting of site reconnaissance,topography survey,subsurface investigation,laboratory testing and backanalysis has been carried out. Rainfall records spanning over a period 42 days before the landslides incident tillthe occurrence of the landslides were compiled and used to examine the relationship between the landslides andthe rainfall. The behavior of these slopes during the rainfall period was examined using a two-stage approach:(1) analyze the infiltration and the ground water flow to obtain the distribution of pore water pressure in theslopes; and (2) analyze the stability of the slopes with the pore water pressure profile obtained in (1). The analysisconfirmed that the landslides were indeed related to the long period rainfall.