Study On Constiuction Risk Evaluation Of Shallow Buried Metro Station

Metro station project is a complex and comprehensive system engineering, engineering scale large, the surrounding buildings and pipeline-intensive, engineering, hydrogeological complex, cumbersome construction, risk concealment and other prominent features. How to evaluate the risk factors of metro station construction scientifically and objectively is an important research content of safe construction. Taking the Yan'an road station of Qingdao metro line 2 as an engineering example, this paper evaluates the construction risk of the shallow subway station. The main contents are as follows:(1) Analyzed the risk characteristics of metro station construction,and studied the mechanism of construction risk of metro station. On the basis of the risk identification of metro station, the risk evaluation index system of metro station construction is constructed by using AHP method. There are six first-level evaluation indicators and 24 second-level evaluation indicators.(2) Constructs the risk evaluation model of metro station construction based on AHP-fuzzy comprehensive evaluation method,and uses the analytic hierarchy process to determine the weight of each evaluation index. The membership degree of evaluation index is determined by expert investigation method.(3) Based on the example of Yan'an road station project, AHP-fuzzy comprehensive evaluation method was used to evaluate the main construction of Yan'an road station. The evaluation grade was 70.53, and the corresponding risk level was Grade II.(4) The evaluation model of BP neural network was established by MATLAB software, and the evaluation model was used to evaluate the risk of each unit segment of Yan'an Road Station. The evaluation results were as follows: the silo section 69.2724, the corresponding risk grade was grade ?; the duct section 67.7417, corresponding to the risk level For the ? level; station main segment 81.9186, for the level ? risk;TBM received guide hole 81.9946, for the level ? risk; TBM origin guide hole 78.5360, for the level ? risk. According to the principle of maximum membership degree, the overall construction risk level of the station is grade ?.In this paper, AHP-fuzzy comprehensive evaluation method and BP neural network evaluation model are used to evaluate the construction risk of Yan'an Road station, and the risk level is Grade II,which is in accordance with the engineering practice. It is feasible to evaluate the construction risk of subway station by using AHP-fuzzy comprehensive evaluation method. At the same time, when using BP neural network for risk assessment, the subway station can be divided into different construction sections, and the evaluation result is made Accurate and reasonable. According to the result of risk evaluation, the specific improvement measures are put forward from the aspects of personnel,management, technology and environment.