Construction Risk Evaluation And Management Of Plateau Expressway Tunnel Based On Fuzzy Analytic Hierarchy Process

Project construction risk runs through the whole construction process and even interferes with the later operation.Risk screening and identification are very important for the smooth progress of construction projects.Tunnel engineering construction risk types are diverse,there are many uncertain factors,therefore,in risk identification,comprehensive use of a variety of methods to carry out a systematic and comprehensive screening of risk factors,establish a complete risk index system,to provide a solid foundation for the accuracy of risk assessment results.In this paper,based on consulting many literatures related to tunnel construction risks at home and abroad,the general risks existing in tunnel construction and the unique risks existing in tunnel construction under the plateau environment are respectively summarized,so as to comprehensively sort out the potential risk factors in the process of plateau tunnel construction.Secondly,the relevant methods of risk identification and analysis are summarized and compared,and scientific and reasonable risk identification management methods are selected to identify the risk factors of plateau expressway tunnel construction,so as to establish the risk assessment system of plateau expressway tunnel construction.Based on the complex characteristics of tunnel construction,the risk assessment model under the guidance of fuzzy analytic hierarchy process is constructed to comprehensively analyze and evaluate the risk of tunnel construction,and specific feasible risk control methods are proposed according to the evaluation results.The main research results are as follows:1)After reviewing the existing literature on the risk of highway tunnel construction,the risk indicators system of plateau highway tunnel construction is established based on a combination of various methods and characteristics of highway tunnel in plateau environment.2)Considering the complexity of tunnel construction in plateau environment,this paper selects the analytic hierarchy process and the fuzzy comprehensive evaluation model to comprehensively evaluate the construction risk,and determines the risk level under each risk indicators,to construct a general risk assessment system for tunnel construction in plateau environment.3)The established risk assessment model is applied to the research case,and the indicators in the general assessment system are screened according to the actual situation of the research case.The results of case study show that the top five risk factors with the highest risk probability are "surrounding rock grade","altitude","ventilation effect","tunnel buried depth" and "entrance form".The analysis results of the maximum membership degree principle show that the risk evaluation result corresponding to the technical management condition is "possible",while the geological condition,environmental condition and scale condition are "accidental".In addition,the comprehensive evaluation results show that the risk level of Labuleng Tunnel is 0.475,and the corresponding risk evaluation result is also "accidental".Therefore,reasonable and appropriate control of risk factors in the construction process can avoid the occurrence of major accidents.