Study On Simplified Calculation Of Liquefaction Lateral Spreading In Gently Inclined Site And Influencing Factors

With the frequent occurrence of earthquakes in China,the deaths,injuries and economic losses caused by all kinds of earthquake damage are innumerable,and the lateral spreading of so1l layer induced by seismic liquefaction 1s one of the most important reasons for the earthquake damage of all kinds of geotechnical structures and structural projects in the liquefaction area.The decisive factor of geotechnical engineering safety is deformation.Based on the seismic safety concept based on deformation control,it is necessary to predict the lateral spreading induced by seismic liquefaction.Whether liquefaction can induce soil lateral spreading and the estimation of lateral spreading has become a research focus in engineering seismology in recent decades.Because the dynamic characteristics of liquefied soil layer involved in site lateral spreading are complex in the process of seismic liquefaction,the variation of pore water pressure of natural soil is difficult to calculate accurately,and the prediction of site lateral spreading under earthquake is a difficult point in engineering seismic research.With the continuous development of dynamic analysis tools such as equivalent linear and nonlinear analysis programs,numerical simulation makes the study of lateral spreading prediction feasible and becomes an important means to study the lateral spreading of liquefied soil layer.DEEPSOIL is an international one-dimensional site seismic response analysis program that uses a non-linear analysis method suitable for simplified lateral spreading calculations.The FLAC3D has the powerful function for simulating the large deformation of the actual site,and can applied for the lateral calculation of the three-dimensional liquefiable sites.1)The dynamic analysis of Wildlife site is carried out by DEEPSOIL.Considering the occurrence of actual liquefaction lateral spreading,the residual shear strength and empirical formula are taken as the important basis for determining yield aceeleration in Newmark sliding blook method.On this basis,the factors affecting the lateral spreading of the Newmark sliding blook method are studied.11)According to the calculation principle of Newmark sliding blook method,a program which can realize acceleration screening and accumulation after secondary integration is built in Excel,and the lateral spreading calculation based on Newmark sliding blook method is realized,iii)Then according to the Wildlife site data recorded by WLA station,the calculated results are compared with the actual records,and the similarities and differences between the simulated surface distribution law and the actual site are obtained.iv)The lateral spreading of several groups of three-dimensional liquefaction site models is calculated by FLAC3D,and the distribution law of surface lateral spreading and the influencing factors of lateral spreading are analyzed.