三峡库区消落区岩体劣化致灾机制研究OA

With the Three Gorges Reservoir entering the stable operation stage,the periodic rise and fall of the reservoir water level has induced rock mass deterioration in the bank slope of hydro-fluctuation belt,which has become an important inducement for a new type of landslide in the reservoir.Field investigations,laboratory experiments,and numerical analysis were used to study the process and disaster causing mechanism of rock mass deterioration in the Kamenziwan landslide.The rock mass in the hydro-fluctuation belt at the front edge of the Xietan riverbank slope exhibited a typical"onion peeling"deterioration characteristic.Tests shown that the wetting-drying cycles could lead to deterioration phenomena such as sandstone erosion and crack propagation.It could also cause changes in the particle connections of the weak layers of mudstone,thereby weakening the shear resistance.Further numerical analysis and research were carried out,and the disaster-causing mechanism of rock mass deterioration of the Kamenziwan landslide was proposed.The results show that the deterioration and disintegration of rock mass in the hydro-fluctuation belt can result in the loss of the resistance to sliding at the front edge of the bank slope.The weak rock layers are further softened and argillized to form a sliding zone.The failure characteristics of the landslide are of the retrogressive type,and the failure mode is of the sliding-tensile cracking type.The research can provide a cer-tain theoretical basis for the prevention and control of landslide disasters in the Three Gorges Reservoir Area.