The Characteristic Of Collapse And Effectiveness Evaluation Of Its Prevention And Control Projects In Sichuan Province

There are many different kinds of geology appearance including mountains and hills located in Sichuan province,and a amount of dangerous and emergency collapse disasters happened due to the frequent earthquake activity and extreme rainfall.After ‘5.12' earthquake,many preventions and control projects are built in a large-scale and the achievements are impressive.However,the failure of projects and recurrence of disasters are still exist nowadays.Hence the effectiveness evaluation of the projects is very important.Based on the project “key technology and method of comprehensive prevention and control for geological disasters”,this thesis focus on a fuzzy comprehensive evaluation method to the evaluate the effectiveness of the projects,which can expand the limitation of quantitative evaluation analysed by traditional statistical methods,besides,this proposed theoretical method can also be taken as a reference for the construction of its preventive works and serve better for the process of the prevention of geological disaster in Sichuan.Referred to the geological documents and research data about the collapse in Sichuan area,this thesis summarized the types and characteristics of collapse in three aspects,which are mechanism,controlling factors and triggering factors.According to 7008 samples of collapse disasters in Sichuan,also including the field research of typical cases where are influenced by earthquake and rainfall,this thesis divided Sichuan area into 3 sections by geological conditions and 8 collapse modes.Then,with the GIS mapping technology and statistical classification method,it summarized the characteristics of each section At the same time,taking the geological and environmental quantitative data as one of geoenvironment indicators,it took the advantages of the ArcGIS for susceptibility mapping of collapses in Sichuan to classify the projects levels in each city.According to the collected reviewed documents of 876 prevention and control projects,this article classified the control projects by active managements,passive protections and auxiliary measures,and accompolished a statistical analysis of monomial and associated measures.Based on the previous steps,it summarized the applicable conditions and areas of each measures and the applicable measures for each type of collapse.Simultaneously,it concluded the parameter design method of the main engineering measures of 130 documents about survey and design of the projects and selected the effective control measures as samples to optimize the engineering design,also stated the causes of the failure of the projects.After analyzed the reviewed documents of 876 projects about its effectiveness,safety and appearance,this thesis considered them as 3 assessment indicators.Moreover,combining with other 3 indicators,which are collapse scale,engineering level and construction period,and it mixed the above-mentioned geoenvironment indicators to establish the evaluation index system of effectiveness.Furthermore,determined each indicator's weight by the distribution of its statistical classification and divided the range of the above indicators into 4 segments objectively.The quantified results were brought into the fuzzy comprehensive evaluation model and the matrix of the evaluation about effectiveness had been calculated.In the mean time,the effectiveness of the projects are classified due to the results.Compared with the classification of the expert reviewed data,the accuracy of the result is 73%.In the end,the BPNN method is verified as a further assessment to prove the effectiveness of the projects.