Study On Safety Risk Management Of Soft Rock Tunnel Excavation Based On Fuzzy Comprehensive Evaluation

With the development of transportation industry,the demand for tunnel construction is constantly increasing.The key to the smooth construction of tunnel is safe excavation.There are many uncertain risk factors in the excavation process of soft rock tunnel,which makes the probability of safety accidents extremely high.Once accidents occur,they often cause extremely serious consequences.In the process of tunnel excavation,the safety risk management of tunnel excavation can make the decision more scientific,reduce the incidence of accidents,and then control the losses caused by accidents.Taking soft rock tunnel as the research object,this paper deeply studies the risk factors in the process of tunnel excavation,identifies and evaluates the risk factors in order to facilitate later management and control,which has high research value and great social significance.This paper consults relevant materials extensively and refers to a large number of domestic and foreign literatures.On this basis,it summarizes the research status of safety risk management in soft rock tunnel excavation at home and abroad.Taking soft rock tunnel as the research object,combining with risk management theory and engineering examples,this paper confirms the relevant theoretical knowledge of AHP,entropy weight method and fuzzy comprehensive evaluation method by introducing the relevant knowledge of AHP,entropy weight method and fuzzy comprehensive evaluation method.Research methods.Combined with relevant literature standards and engineering examples,the risk factors affecting the excavation safety of soft rock tunnel are identified by literature review method,and the safety risk evaluation index system is preliminarily constructed.It is found that there are unreasonable factors in the preliminary selection of evaluation indicators,and the whitening weight function is introduced to screen and optimize the indicators to form the final risk evaluation index system.According to the principle of combination of subjective and objective,the weight of risk evaluation index is calculated.The subjective and objective weights of evaluation index are calculated by analytic hierarchy process(AHP)and entropy weight method respectively,and then the combined weights of evaluation index are obtained by calculation.Finally,taking Yangjiawan Tunnel Project as an example,on the basis of the established fuzzy comprehensive evaluation model,the first-level fuzzy comprehensive evaluation and the second-level fuzzy comprehensive evaluation are carried out respectively.Through calculation and analysis,the risk grade of Yangjiawan Tunnel Project is determined to be"general risk",and the evaluation results basically conform to the actual situation.This paper analyses the influence of various risk factors on the excavation safety of soft rock tunnel.Through the combination of theory and practice,good results have been achieved in the safety risk control of tunnel excavation.Through the research of this paper,it can provide reference for similar projects and provide reference for fine excavation construction of soft rock tunnel.