| As a common form of accumulation body in Canyon river section,the evaluation method of initial stability and dynamic stability is very important for emergency treatment and safe operation of long channel after disaster.In order to find out the sensitive factors that affect the stability of the river channel invaded by the accumulation body and to propose a dynamic stability evaluation method for the channel accumulation body,this paper studies the stability of influencing factors and the stability of the stability of stacks with different slide angle,different thickness,and different soaking water level by means of numerical simulation.The main research results are as follows:(1)It is found that the failure modes of the channel accumulation body mainly include the scour local failure mode and the immersion softening failure mode of the water level.(2)On the basis of statistical analysis,in the accumulation body of the waterway formed by the collapse-slip disasters in the Chongqing-Yichang section of the upper reaches of the Yangtze River,the accumulations with average slope angles more than 20 degrees and less than 35 degrees are the most common,followed by the accumulation of the average slope angle of the slide surface at less than 20 degrees;Statistical analysis showed that the upper reaches of the Yangtze River in Chongqing-Yichang section of landslide disaster formation average deposition thickness is less than 30 m the most common accumulation.(3)Most of the initial state of the intrusive channel deposits in the canyon river is stable.After a period of wetting and softening,for soil-stone mixed accumulation body with less than 30% of block stone content,soaking and softening will cause the sliding zone of the invaded channel accumulation body to saturate and then collapse again.The effect of soaking and softening on the stability of the invaded waterway accumulation body is not significant for soil-stone mixed accumulation body with more than 30% of block stone content.In engineering practice,that the stability of soil-stone mixed accumulation body with less than 30% of block stone content invaded into a channel should be considered.(4)The change of the water level is an important factor affecting the stability of the accumulation body.The immersion of the water level into the accumulation body of the waterway will reduce the shear strength of the sliding surface of the accumulation body and at the same time it will produce the floating support to the accumulation body of the waterway,which may occur during the process of the river changing from low water to high water level.Again,slide and destroy.The decline of the reservoir water level is another important factor affecting the stability of the accumulation body.The decline of the reservoir water level will produce the seepage force in the direction of the surface in the accumulation body,and then reduce the stability of the accumulation body.Therefore,in engineering practice,the influence of water level variation on the stability of the invading channel accumulation body should be emphasized.(5)The failure modes of the accumulation body of the landslide mainly include the mode of erosion and local collapse and the soaking and softening failure mode of the water level.It is suggested that the infiltration rate of the accumulative body should be closely observed in the engineering practice.In order to better judge the stability of accumulation body. |
