Study On Characteristics And Harmfulness Of Zhaojia Shan Landslide-Debris Avalanche In Qingchuan County

A large number of geological disasters have been triggered during the "5.12" earthquake. Due to its ultra far runout and fast movement, landslide -debris avalanche can often lead to disastrous consequences, resulting in serious loss of life and property. Some related landslide-debris avalanche were analyzed, and based on ZhaoJia Shan landslide -debris avalanche in Qingchuan County, the characteristics and harmfulness were analyzed and studied through field investigation and analysis, drilling and other means.ZhaoJia Shan landslide -debris avalanche is located in Qifo Township, Qingchuan County, Sichuan Province. According to the motion characteristics and its distribution, the avalanche can be divided into sliding source area, the impact of the barrier zone, projectile motion and deposition area, whose volume is about 4.11×105m3. The width of disaster body is about 100m, from the trailing edge to the leading edge is about 1000m,it occurred two hours after the "5.12"earthquake.The landslide -debris avalanche has an irregular shape, which can be divided into slip source region, impact barrier zone, projectile motion and stacking area. It rises to the slip source region, then blocked by the front of the drum hill mountain, thus forming a shock barrier area, then due to topography and other reasons, generate movement and accumulation, formed projectile motion and stacking area.ZhaoJia Shan landslide-debris avalanche was triggered by the strong vibration of the "5.12" earthquake and it’s special terrain conditions. There is a gap of 390 meters between the top of the source region and the leading edge of the accumulation area. In this paper, based on the current situation, not only evaluated the slope stability for quantitative analysis but also analyzed the landslide and debris flow secondary disaster chain. According to the guiding rules and control principle of geological disaster prevention, combined with the occurrence condition, the activity characteristics and the rule of the disaster, put forward the control scheme on the basis of comprehensive consideration of the workload, construction arrangement, capital investment, prevention and control effect, and so on.