Back analysis of unsaturated parameters and numerical seepage simulation of the Shuping landslide in Three Gorges reservoir area

摘要

Obvious ground deformation and displacement occurred in Shuping Landslide in Three Gorgesreservoir in June 2003,when the reservoir level reached to EL. 135 m. Rainfall and the change of groundwaterseepage caused by raise of reservoir water level are the main reasons of landslide deformation. Groundwatermovement in landslide mass is a kind of unsaturated and unstable seepage flow,which should be analyzed bythe theory of unsaturated unstable seepage. Before the analysis,the determination of parameters is the primaryproblem. Based on the observed rainfall and water level of drill holes in the landslide area in July 2005,orthogonaloptimizing method was used to conduct back analysis for getting the seepage parameters. After that,numericalsimulation of groundwater seepage in Shuping landslide mass was carried out by considering real situation ofreservoir water level changes. The variation of groundwater seepage in landslide area with the reservoir waterlevel changes was analyzed. The research results will provide useful information for predicting landslide stabilityunder the action of reservoir water level.