| With the development of society and economy,some unreasonable development patterns of human beings and the change of natural environment,which have led to the frequent occurrence of landslide and other geological disasters,and landslide disaster occupies a large proportion of the six types of geological disasters.The severity and multiple of landslide disasters have directly affected all aspects of people's life,and it has the characteristics of wide distribution?large scale?large quantity?high risk and so on,in addition to the impact of climate change and other factors,the frequency and intensity of the landslide disaster are increasing,casualties and economic losses caused by landslide disaster also increasing,while the risk assessment is an indispensable section to control the disaster risk and reduce the loss,which is a comprehensive study of the theory of social economy and natural science.Therefore,through a risk assessment of landslide risk based on the comprehensive analysis of the influencing factors of landslide disaster,useing the theoretical analysis and numerical analysis to analyze the landslide disaster.Based on the theory of risk assessment,considering the various factors affecting the landslide risk,using the factor analysis method to filter the index system,and determine the weight of the index,calculating the risk coefficient of total effect by the efficacy coefficient method,and analyze the risk of landslide disaster in Xichong village,in order to verify the reliability of the efficacy coefficient method,the fuzzy comprehensive analytic hierarchy process(AHP)is used to verify it.Study on the change of pore water pressure of landslide in Xichong village landslide under rainfall condition by GeoStudio,and analyze instability probability of landslide under rainfall condition,formulate corresponding strategies for disaster prevention and mitigation,which is great scientific and practical significance to protect the life and property safety of the people in the study area.And draw the following conclusions:(1)On the basis of penetrate deeply study of regional topography,lithology,geological structure and natural and artificial factors,Taking 14 landslides in the study area as an example,and using the factor analysis method to analyze.The main controlling factor of landslide is Engineering rock group,slope,aspect,sliding volume,7 day maximum rainfall,vegetation coverage,excavation slope,fault effect,river influence distance.The weight of each main control factor:?_i=(0.024?0.096?0.211?0.061?0.175?0.082?0.241?0.048?0.062),The efficacy coefficient method is used to verify the 14 landslides,in addition to the 1 landslide risk level is high,the4 is low,the rest of the landslide is consistent with the actual level,which show that the method is proved to be practical.(2)Combining with the method of efficiency coefficient model and the weight of main control factors,Further analysis on the Risk of Landslide disaster in Xikou Village,the total effective coefficient of Xichong landslide hazard is 85.17,the risk grade is?,the fuzzy comprehensive analytic hierarchy process(AHP)is used to verify the risk of landslide in Xichong,and it is concluded that the landslide risk of Xichong village belongs to?grade,which is more dangerous.It shows that it is feasible to evaluate the landslide risk by using the method of efficiency coefficient.(3)Based on the Monte Carlo method,combined GeoStudio numerical analysis software to analyze instability probability of Xichong village,studying the variation law of pore water pressure and permeability coefficient of unsaturated soil under the conditions of rainfall intensity and rainfall duration.The seepage field of Seep/w analysis is introduced into the landslide stability calculation,studying the variation law of stability coefficient and failure probability of landslide,the results show that the risk level of Xichong landslide is the?grade at two condition,belong to high risk,corresponding to the results of previous theoretical analysis. |
PDF Full Text Request