Entrainment Effect Analysis Of The Rapid And Long Runout Landslide Induced By Earthquake

A lot of debris flow geological disasters were induced by WenChuan earthquake and it has caused tremendous losses to life and property and economic level.Because of entrainment effect of debris flow is the main reason for rapid and long runout landslide,more and more scholars made attention and enlarged to make a study on debris flows induced by earthquake since then.Even through many people have made some progresses on entraiment effect of debris flow,it has a long space to know entraiment effect of debris flow induced by earthquake.In this paper,the different factors affecting entrainment effect of debris flow had been made by physical model experience,the computational setting out formula of landslide induced by earthquake was deduced,the entrainment mechanism of landslide was discussed and a analysis model for entrainment effect of debris flows under static and under earthquake were built respectively.The entrainment depth of debris flow under static and under earthquake was getted combined with two rheological models.At last,the model was proved feasibility and correctness by Wenjia Valley landslide induced by earthquake.The main research work is as follows:Firstly,physical model experience was conducted according to Wenjia Valley induced by Wenchuan earthquake.The factors affecting entrainment effect of landslide induced by static and earthquake were researched repectively.Accordingly,the computational setting out formula of landslide induced by earthquake was deduced and the entraiment mechanism of landslide is else discussed.Secondly,the criterion of entraiment effect of debris flow is put forward and the entraiment force of debris flow is calculated.So the entraiment length of debris flow is obtained based on the balance formula between the entraiment force of debris flow and the soil shear strength of basement.Thirdly,a model for geotechnical analysis of debris flows was built and the entraiment depth formula was calculated combined the computational setting out formula of landslide and the different rheological model of the landslide mass.The method was used to analysis the sliding velocity,the sliding shape,the entraiment depth under static and under earthquake and the contrastive analysis is conducted to actual physical model experience.At last,the analysis model for entrainment effect induced by earthquake was applied to calculate the WenChuan Valley landslide induced by earthquake and the sliding velocity,the sliding distance,the entrainment depth was forecasted.In order to prove the feasibility and correctness of this calculation method,the forecasting result is used to compare with the result of actual measurement,numerical simulation and physical model experience.The result shows that theoretical analysis is relatively validity and feasibility and this calculation model is proved to be corrected.