Study Of Method Of Hazard Zoning For Earthquake Triggered Landslides And Disaster Alleviation Of Line Selection In High Intensity Mountain Area

A large number of real seismic data show that the earthquake triggering landslide is the main cause of road engineering damage.The Jibson slope of permanent displacement prediction formula based on Newmark block model is currently the only method to evaluate the risk of earthquake triggered landslide from the perspective of deformation damage and Overall failure probability of slope.Checked by Seismic data of the "5.12" Wenchuan earthquake,The calculated value of Jibson method is smaller than the measured displacement of the slope.Theoretical analysis shows that the slide model does not consider the attenuation effect of the shear strength of the sliding surface during the earthquake,which leads to the small calculation value of the displacement prediction method.In view of this,the Newmark slide model is modified by adding the attenuation coefficient to the effective internal friction angle and effective cohesion of the rock mass of the sliding surface.Based on the correction,We refer to the method framework of Jibson slope failure probability model,and take the real earthquake data of Wenchua2 n earthquake to establish the criterion of danger zoning for earthquake triggered landslide with surface density as zonation index.The correctness of the zoning method is tested by using the real earthquake data of the "4.20" Lushan earthquake.The results of the paper are as follows:Firstly,By comparing the calculated values of the Jibson displacement prediction method with the seismic data of the Wenchuan seismic slope displacement,The accuracy of the Jibson prediction method is tested,and the conclusion that the calculated value of the Jibson method is smaller than the real earthquake value is obtained.On the basis of the Newmark slider model based on the theoretical basis of the Jibson method,the reasons for the smaller calculation value of the model are analyzed.In this theory,the shear strength of the slope in the earthquake process is regarded as a constant value,and the attenuation effect of the shear strength of the sliding surface of the slope is ignored.This discovery provides a theoretical basis for the correction of the Newmark model.Secondly,According to the vibration of the front sliding soil direct shear test,the vibration of direct shear test and dynamic triaxial test three,considering the earthquake intensity is the most common VIII,IV,The attenuation coefficient of the cohesive force and the internal friction angle of the shear strength parameters of the sliding surface is 0.6 and 0.85,respectively.The critical acceleration of the slope becomes 0.7 times that of the original.By adding the attenuation coefficient method,the modified formula for calculating the critical acceleration ratio displacement of Jibson is obtained,and the prediction accuracy of the formula is improved to a certain extent.Thirdly,On the basis of the modified Jibson displacement prediction method,the modeling idea of the slope instability probability model is referred to,The quantitative relationship between the Newmark permanent displacement and the surface density of the landslide is established by using the data of the landslide surface density extracted from the Wenchuan earthquake.A set of methods for the hazard zoning of earthquake triggered landslides and landslides is proposed,which is based on the risk index of the landslide surface density.The rationality of the zoning method is verified by the data of Lushan seismic surface density.The results show that the zoning result is consistent with the actual situation,indicating that the zoning method has certain guiding significance for the actual project.Finally,The use of this earthquake triggered landslide Landslide Hazard Zoning Method of seismic landslide hazard zoning of Sichuan Tibet highway in Linzhi-Bomi region,in order to provide some help and guidance for prevention and treatment of local earthquake landslide and early warning.It can not only predict the severity of coseismic collapse and landslide,but also contain information about the environmental changes in the mountain disaster after the earthquake.It can provide scientific basis for road route selection design in high intensity earthquake mountain area.