Environment Impact Risk Management Of Metro Station Construction In Zhengzhou

This paper takes Zhengzhou subway station project as the background, which is a projectof three-layer interchange station underground with a large excavation area and complexsurrounding environment. The paper uses the methods of numerical simulation before workand field measurement combined with risk prediction during construction to conduct researchon risk management of the project construction environment. Numerical simulation is aneffective way to understand the engineering risk in advance. Engineering data is an importantbasis for project safety. The prediction of monitoring data for a certain period of time in thefuture based on engineering monitoring data can reflect security trend of the project. It isconducive for project risk management on site to quantify the monitoring data and predictiondata for risk classification. This paper mainly carries out the following work:Simulate deformation of continuous walls during excavation inside the station anddetermine the range value of large deformation of continuous walls and the maximumdisplacement using ABAQUS software to establish a three-dimensional model to conduct riskprediction for the construction of subway station. In order to analyze the influence offoundation pit excavation on surrounding underground pipelines, the paper first establishes aplane model, and then analyzes the influence of foundation pit excavation on undergroundpipelines under two conditions of no support and internal support. Results show that exertinginternal supports in the project can effectively reduce the displacement of undergroundpipelines. Afterwards, establish the three-dimensional model to study the deformation laws ofpipelines in different positions from the foundation pit during the excavation of foundation pit.Results show that the vertical displacement of pipelines adjacent to the foundation pit sinksmost in the early stage of excavation, and both sides decrease successively. With the increaseof the depth of excavation, the vertical displacement of pipelines turns upward and thehorizontal displacement makes excursion towards the external direction of foundation pit.Conduct comprehensive monitoring of building envelope of the project, surroundingsettlement and strut axial force through the method of field measurement, and focus on theanalysis of the test data of retaining structure and ground surface settlement, then analyze thechange laws of the project and the surrounding environment during the excavation. UseElman neural network to predict the settlement of the top of continuous walls and horizontaldisplacement of the wall body. Results show that the trend of predictive value and measuredvalue tends to be consistent, the location of the maximum is slightly behind the monitoringvalue, and they are in good agreement. We conclude that utilizing trained Elman network topredict latter deformation based on the early monitoring data can provide some guidingsignificance for risk warning, risk assessment and risk management during the construction inthe future.Give the computational formula combined with the characteristics of environment risk ofthe station project and the concept of risk early warning and introduce the risk index. Provide the method of converting monitoring data and prediction data of the project into risk level andrisk index fitting of different projects to assess environmental risk of the project, and makerisk classification of the risk of continuous wall displacement by engineering practice.Combined with the work of risk management organization and risk managers on site,focus on the control measures of surrounding buildings and underground pipelines during theconstruction based on the basis of numerical simulation before work, risk prediction and riskrating during construction for risk management of project environment.This paper combines the prediction data obtained by the method of numerical simulationand Elman neural network with monitoring data, which provides the basis of making on-siterisk management measures and conducting on-site risk management during construction ofthe station. This paper wishes to give some guidance and reference for risk managementduring the construction.