YIN Yueping, WANG Luqi, ZHAO Peng, ZHANG Zhihua, HUANG Bolin, WANG Xuebing

Abstract: This paper studies the damage evolution of the high-steep reservoir banks caused by the water storage operation of the Three Gorges Project. It is prone to become unstable for the rocky bank located in the canyon area with the dual geological structure of hard at the upper and soft at the lower layers. The strength of the base rock mass in the fluctuation zone tend to decrease due to the deterioration. On the basis of on-site investigation and long-term monitoring, the damage constitutive models of base rock mass under dry, saturated, and transition states were established. A quantitative evaluation method was proposed, and the ratio of the peak stress to the effective stress of the fluctuation zone was used as the stability factor of the crashed failure. The application research of Jianchuandong dangerous rock mass in Wuxia Gorge was carried out. The results showed that the stability evaluation method proposed in this paper could track the evolution states of macro slump, deformation and nonlinear increase of base pressures. Compared to the traditional limit equilibrium stability analysis method, this new method could reflect the process from damage to collapse. As for the crashed failure of high-steep rocky bank, the reinforcement program of the base rock mass was formulated. The related contents can provide guidance for the risk management of high-steep rocky bank in the Three Gorges Reservoir Area.

Keywords: Three Gorges Reservoir, high-steep reservoir banks, damage evolution, crashed failure