Failure characteristics of the reservoir landslide and surge calculations

Affected by the fluctuation in water levels in reservoir areas, the probability of potential landslide instability along reservoir banks is substantially increasing, which threatens the lives and property of residents along the reservoirs. In this study, the effect of reservoirs on the Dashuichong landslide in Hunan Province, China, was investigated. The geological background and failure characteristics of the landslide were presented. The crack features and surface deformation mechanisms were described in detail, and the surge characteristics of the landslide at the highest water level (333.15 m) were calculated. The deformation characteristics and failure mechanisms of the Earth’s surface and overlying buildings revealed that the instability of the landslide was mainly affected by the fluctuation in the reservoir water level and that initially the toe of the slope near the reservoir bank slipped, gradually extending to the top of the slope, forming a typical traction landslide under the influence of the reservoir water. At the highest water level (333.15 m), the landslide sliding velocity of the landslide into the reservoir was 1.43 m/s, causing the initial height of the surge to be 2.45 m and the run-up height of the surge on the reservoir dam to be approximately 3.67 m. These conditions readily induced the risk of dam overturning.