| Landslide-generated waves are a type of gravity wave caused by the entry of landslide bodies into water,characterized by high speed,high energy,and a wide range of impact,which can pose significant threats to reservoir areas and downstream regions.The unstable volume of the rock-soil mass in the Dashishu landslide area of the Xiaolangdi Reservoir is approximately 4.5 million m~3.If a landslide occurs,it will seriously threaten the safety of surrounding personnel and buildings.This study takes the Dashishu landslide as the research object,using FLAC3D and FLOW3D software to numerically simulate the stability of the landslide and the size of the first wave and its propagation process.The research results will provide theoretical support for emergency measures against landslide-generated waves in the Dashishu landslide disaster.The main research content and results are as follows:(1)Based on FLAC3D software,the three-dimensional stability of the Dashishu landslide under different water storage levels,rising and falling water levels,high water levels,and seismic coupling effects was analyzed using the strength reduction method.The results show that the higher the water storage level,the lower the slope stability.Compared with the static water level,a dynamic rise in the water level can slightly enhance the slope stability,while a sudden drop in the water level can reduce the slope stability.High water levels and seismic coupling effects have a significant impact on the slope stability,which can reduce the slope stability coefficient to 0.924.(2)Based on FLOW3D software,the granular flow model and drift flux model were used to numerically invert the physical model experiment of granular flow landslide-induced waves.The flow pattern of the granular flow and the generation and propagation patterns of the waves in the numerical simulation are consistent with the physical experiment.The difference between the maximum wave height in the numerical simulation and the physical experiment is less than 5%,confirming the reliability and applicability of FLOW3D in simulating granular landslide-induced waves.(3)Based on FLOW3D software,a numerical simulation of the three-dimensional terrain of the Dashishu was conducted.According to the numerical results at a water level of 230m,the direction of maximum wave propagation was inferred,and the mesh size of the model was determined.The river model was adjusted based on the direction of maximum wave propagation.The influence of water depth on the size of the first wave was also explored.The results show that as the water depth increases,the first wave height and maximum wave height before the dam gradually decrease.At a water level of 275m,the maximum wave height before the dam is 1.53m,and at a water level of 230m,the maximum wave height before the dam can reach 4.54m.No overtopping occurred,making it relatively safe for downstream residents and buildings. |
