Institute Of Geophysics,China Earthquake Administration Doctoral Dissertation

Landslide disaster is the most common secondary disaster caused by earthquake.Presently,China is in the period of rapid development and a lot of large-scale projects are under construction,which related to dynamic stability of slope.Therefore,the research on the dynamic stability of slope under the earthquake has become a hot problem which attracts the attention of the experts.Now many literatures used single-sided slope model to research on earthquake response and damage mechanism.However,Wenchuan earthquake has caused many thin ridges damage,which are typical double-sided slopes and have significant amplification effects.Due to the characteristics of strong nonlinearity,anisotropy and heterogeneity of soil slope,its dynamic response is more complex,so the paper takes double-sided soil slope as the research object,discussing its dynamic response law under earthquake action and dynamic characteristics under different influencing factors.The main results are as follows:(1)The stability of single and double side slopes was analyzed for different values of four parameters,including slope angle ??slope height h?cohesive strength c?friction angle ? based on the FEM strength reduction method,the penetrating plastic strain zones on two sides of the double side slope always appear after them intersection,then displacement inflexion of double slope is earlier than that of single side slope.In other words,safety factors of the single side slope are slightly larger than those of double side slope;when the penetrating plastic strain zone does not appear and displacement inflexion of two kinds of slopes appears at the same time,so the safety factors of the two kinds of slopes is consistent.(2)As the height increases,the acceleration amplification factors of double-sided slope show a trend of rhythmic change in vertical direction,and reach the maximum at the top of slope.Along the slope direction,the acceleration peak amplification factors show a trend of decreasing first and then increasing later,and reach the maximum at the slope shoulder.(3)When the acceleration amplitude is lager,the acceleration amplification effect of the upper and middle part of slope is more significant.With the increase of the constant amplitude of acceleration amplitude,the deformation amount of slope will increase equidistantly.(4)A dimensionless proportional coefficient ? of two-sided slope is proposed,which is the ratio of slope top width to slope horizontal distance.When ?<0.5,the acceleration amplification factors of slope shoulder increase rapidly with the decrease of slope top width,and both of them are greater than the corresponding value of single slope.When ?>0.5,the slope shoulder acceleration amplification factor tends to be stable as the slope top width increases gradually,but all of them are slightly larger than the corresponding value of the single slope.When studying the dynamic response rule of double-sided slope,? =0.5 is a transition point from double-sided slope to single-sided slope.(4)The smaller the top width of the double-sided slope is,the greater the vertical displacement of the slope shoulder is.With the increase of the top width,the vertical deformation of the double-sided slope shoulder is gradually close to that of the single-sided slope.