Three-dimensional system monitoring and numerical simulation on the dynamic deformation process of Jiaju landslide in Danba, Sichuan

Affected by Qinghai-Tibet Plateau tectonic structures, numerous accumulations slides which have the characteristics of multiple formation types, complex mechanism, sudden occurrence, difficult to predict the developing trend, huge damage, etc., are distributed in Southwest China. Among of them, Jiaju landslide, which locates at the upper reach of Dadu River, is a typical ancient one with dramatically thick depth and localized resurrection tendency. A comprehensive monitoring system including GPS, InSAR and Inclinometer has been carried out to monitor both surface displacement and deep displacement. The result shows that Jiaju landslide nowadays is at an evolutionary stage with accelerating deformation in the surface and slow deformation in the deep body. And further analysis of the monitoring results indicates the deformation and failure modes are the combination of sliding and compression cracking in the surface and fracturing in the deep position. In order to testify the monitoring results, FLAC3D numerical simulation method is adopted and the stress field, distribution of displacement and plastic zone in the dynamic deformation process for Jiaju landslide are all simulated; and simulation results are consistent with monitoring results.