Research On Construction Risk Evaluation Of Subway Foundation Pit Engineering

With the continuous advancement of urbanization,urban traffic pressure is aggravated day by day.In order to ease traffic congestion,more and more cities choose to build subways.However,the subway foundation pit engineering has the characteristics of long construction period,wide influence range,many factors involved,high degree of complexity and strong concealment,which makes the subway foundation pit engineering in the construction of the construction risk is great.Under this background,this paper from the perspective of construction enterprises,the subway foundation pit construction risk evaluation research,analysis of the subway foundation pit construction risk evaluation workflow,and put forward the risk response measures.This paper firstly analyzes the current situation of risk evaluation of subway foundation pit construction,and briefly analyzes the problems existing in the construction of risk evaluation index system and weight calculation.On this basis,the coupling matrix method of job-risk decomposition is used to decompose the work and risk units,and the artificial intelligence model is used to analyze the risk causes.Then,the risk factors are summarized and sorted out,and a risk evaluation index system including 8 first-level indexes and 59second-level indexes is obtained,including the construction risk of the enclosure structure,the foundation pit dewatering risk,the foundation pit treatment risk,the foundation pit excavation risk,the main structure construction risk,the natural risk,the geological risk and the environmental risk.After that,the interaction between risk factors is further analyzed,the weight calculation is carried out by using the analytic hierarchy process(AHP),and the risk evaluation model based on the cloud theory is constructed,and the working procedure of risk evaluation is formed.Finally,risk analysis is carried out on the project of Dongcheng West Station of the East extension section of Guangzhou Rail Transit Metro Line 3,and the construction risk level of the project is calculated as "general risk",and the accuracy of the results is verified by comparative analysis,and then according to the construction risk evaluation results and the actual situation of the site,countermeasures are proposed to reduce the construction risk of the project.Through the analysis and research of this paper,a relatively complete risk assessment process has been formed,which can provide construction risk assessment methods with strong science,strong objectivity and high accuracy for subway construction enterprises for reference.