IN-SITU GPS MONITORING AND NUMERICAL SIMULATION OF SLOPE DEFORMATION AND STABILITY IN EARTHQUAKE

摘要

The Ya'an earthquake triggered the Wujiashan old landslide instability.The region deformation has monitored by an in-situ GPS monitoring system.In this paper,GPS data is firstly analyzed.Furthermore,FLAC3D is used to establish the model of deformation areas to simulate the landslide process by loading seismic wave,which is based on the regional geological parameters of landslide.The actual deformation monitored by the GPS system shows that the slope in the Wujiashan region had been in a steady state with little deformation before Ya'an earthquake happened,when Ya'an earthquake occurred,however,the slope deformation increased rapidly and the maximum values was approximately 43.72 mm in the vertical direction and 26.65 mm in the horizontal direction,which means earthquake seismic had led to significant reduction in the slope stability and caused this slope failure.Results of FLAC3D numerical simulation show that dynamic response degrees in different soil layers are different under the same earthquake magnitude and old landslide is more sensitive.From the comparison of the actual and numerical deformation,deformation law can be investigated and served as a reference.