Research On Sliding And Blocking River Mechanism Of Tangjiashan Landslide

A great number of landslides induced by "5.12" Wenchuan earthquake show that the failure of cataclinal rock slopes induced by earthquake forces account for the maximal percentage. Tang Jiashan landslide is a typical high speed bedding glide in a middle-steep dip angle. The whole time of sliding which earthquake sprung is about semi-minute, and its relative displacement is 900 meters. Meanwhile its gliding speed which is speculated is about 30 meter per second. The length of The barrier dam which is formed by the high speed landslide along the river is 803.4 meters, and the maximum of the width crossing the river is 611.8 meter. The height of the dam is between 82 and 124 meters, and its average of area is about 300 thousand square meters, and its volume is estimated about 20.37 million stere. because of the particularity of the location and the enormous potential dangers to the upstream, not only do countrymen worry about these but these questions attract the world's attention. The mechanism of stopping river up and the possibility of dam-breaking have been the focus of the scientists in geology and geotechnical. Based on the related researches,the slope stability under seismic loadings and the mechanism of high speed-landslide sliding is studied in this paper.The concrete research contents and main anchievements are as follows:(1) The causes influencing stability of slope under earthquake are analyzed,the internal causes such as geologic structure,structural types of rock mass,rock character of strata,landform and geomorphology,hydrogeology,and the external causes such as seismic loading,artificial factors are discussed in order to instruct the design and stabilization of slope.(2)The fatigue strength theory is used to simulate the mechanical properties's changes of the cataclinal rock slopes under the action of the earthquake forces. And by simplifing seismic waves as elastic waves to generate equivalent static stresses on cataclinal structural plane. Through taking the TangJiashan slope as example, the rationality of the failure criterion(3) On the basis of the detailed geologic investigation results which was got on the locale of the barrier dam, the forming process of the landslide can be summarized as follows:earthquake induce that the rock break and disjoint-sliding(sitting quickly)-eroding the fluvial sand and pebbles like pancake turner in the forward side and middle side-the explosion flung crab the vegetation such as trees on the opposite hillside-the barrier dam form.