Research On The Risk Management Of Earth Pressure Balance Shield Under Surface Water

With the continuous development of urbanization in China,the scale of urban rail transit construction continues to expand.The shield tunneling projects that cross the surface water bodies(rivers,rivers,lakes,and seas)are becoming more and more popular.The construction environment of the shield tunnel under the surface water body is relatively complicated.The poor hydrogeological conditions along the line will have a great impact on the shield construction.The risk of changing the cutter under the river and the risk of the earth pressure balance shield crossing the rich water formation are extremely difficult to bring about unbearable impact on the construction of the project.Therefore,it is necessary to study the construction risk of the shield crossing the river.In this paper,the development process of shield construction technology is briefly introduced,and the technical of shield tunnel construction is studied.Model the mechanism of security risk and analyze the causes and evolution of risk accidents.This paper analyzes and statistics more than 50 typical shield construction safety accidents,and combines the relevant shield construction risk safety research literature,and uses WBS-RBS method to identify the safety risk of shield construction.After obtaining the risk list,build a security risk indicator system.The analytic hierarchy process is used to calculate the weight of each risk factor.The fuzzy comprehensive evaluation method is used to evaluate the risk occurrence level and risk loss level,and the risk matrix method(R=P×C)is used to classify the risk.Finally,this paper conducts an empirical study on the Dongwan section of Foshan Metro Line 3.After the risk identification and analysis of the actual project,specific technical countermeasures are formulated for major risk sources,and it is hoped to provide reference for similar engineering construction risk management research.