A numerical analysis of rock creep-induced slide: a case study from Jiweishan Mountain, China

摘要

Landslides and slope failures are very common phenomena in hilly regions, Southwestern China. These are hazardous because of the accompanying progressive movement of the slope-forming-material. To minimize the landslide effects, slope failure analysis and stabilization require in-depth understanding of the process that governs the behavior of the slope. The present paper first briefly describes a three-dimensional numerical brittle creep model for rock. The model accounts for material heterogeneity, through a stochastic local failure stress field, and local material degradation using an exponential material softening law. Then a case study of the Jiweishan rockslide that occurred in China is numerically investigated considering the effect of the mining activity. Numerical simulations visualize the entire process of the Jiweishan rockslide from the fracture initiation, propagation and coalescence. The distribution and evolution of associated stress and deformation field during the slide are also presented. Numerical simulations show that the underground mining excavations have remarkably negative effect on the stability of the rock slope, which is one of the important triggering factors of the rockslide. Moreover, it is possible to take some precautions for the unstable failure of rock mass by monitoring acoustic emission (AE) events or mi-croseismicities since the occurrence of clusters of AE events prior to the final unstable rockslide. The results are of general interest, because they can be applied to the investigation of time-dependent instability in rock masses, to the mitigation of associated rock hazards in rock engineering, and even to a better understanding of the seismic activities in geological and geophysical phenomena occurring in the earth's crust.