Risk Management Of Foundation Pit Construction In Ningbo Textile City Metro Station

Ningbo is an important coastal port city in Southeast which belongs to China’s firstgroup of opening to the outside world and is the south of the Yangtze River Delta economiccenter. In recent years as the economic development becoming rapider, the tempo of cityconstruction apparently faster, rail transit construction heat also enhanced, subsequentlyemerged in many subway station foundation pit engineering. In terms of engineeringgeological, because of major soft soil in Ningbo, Influence foundation pit safety uncertaintyfactors becomes more complex and the construction risk much more than the general soillayer. it makes that deep foundation pit engineering research of risk management in soft soilarea has become particularly important.In this paper, based on the Ningbo Subway line2Textile City Station constructionproject, we have a detailed analysis and evaluation for the risk of the subway stationfoundation pit engineering, And also put forward the corresponding risk control measures toguide the construction.Firstly, based on cognition of the basic principles and methods of risk and risk analysis,combined with the reality of subway station engineering, we constructed the basic theoreticalframework of the subway station construction risk analysis.Secondly，this paper proposes the technical problems of this project after the analysis ofthe engineering situation. Then this paper analyzes the possible risks.Thirdly， the total risk of this project could be decomposed in three first levelrisks-foundation construction risk, the around damage risk and natural disaster risk. And theycould be decomposed in many lower level risks. Then in the basis of expert investigation,this paper uses the Analysis Hierarchy Process (AHP) to evaluate all level risks, andcalculates the weight and risk level of all level risks, finally makes the decision of risks.(4) In the basis of risks assessment, this paper analyzes the inducement of four key risksin detail, they are construction of diaphragm wall risk, foundation excavation risk, erectingsupporting risk, environment and storm risk. Then this paper proposes the measures of riskmitigation, emergency handling and system assurance. The management and controllingmeasures of risks guide the construction of foundation successfully.