Research On Risk Management And Control System Of Subway Deep Foundation Pit Construction

Due to the concealment,complexity and unpredictability of urban rail transit construction project,the construction risk faced by the project is very large.In view of this,this paper puts forward a complete risk management and control system research scheme through the field investigation of Nanning and Ningbo urban rail transit existing risk management system,combined with the research and development of its own team risk management information system.From the two functional modules(static risk assessment,dynamic risk control)to discuss the system content,from the theoretical methods(analytic hierarchy process,network analysis,membership function,artificial neural network,etc.)to explain the development process,and finally come to a set of feasible and reasonable system building scheme.The main contents of this paper and the conclusions are as follows(1)Due to the complex relationship between many risk factors in the construction of deep foundation pit,the simple superposition method of individual risk can not objectively and truly reflect the relationship and reduce the credibility of risk assessment results.Therefore,based on AHP,this paper uses network analysis method to express the complex correlation degree of various risk factors.The weight of each individual risk is calculated,and then the overall risk is obtained.Through the actual case analysis,the credibility of the calculation results is significantly improved compared with the network analysis method.(2)In the construction,the individual risk will disappear and appear with the change of the construction period,so the static risk assessment results can not play a guiding role in the dynamic construction.Therefore,this paper first introduces the concept of exposure degree to redefine the risk value,and then uses the membership function in fuzzy mathematics to endow the individual risk time attribute,so as to realize the dynamic risk assessment which can change with the construction period,and can better evaluate the overall risk under different construction periods,the example in this paper shows the advantages of this method.(3)In the dynamic risk management and control,the horizontal displacement of retaining structure has strong directivity to the safety assessment of deep foundation pit engineering,so how to analyze and predict the change of horizontal displacement of retaining structure is very important.In this paper,BP artificial neural network is used to predict the horizontal displacement of retaining structure.Compared with the actual monitoring value,the error accuracy can reach 1 mm,it can provide reference for construction monitoring.(4)According to the actual investigation results of the risk management and control system of multiple regional rail transit companies,this paper proposes that the system should use BIM Technology to realize construction visualization,and should combine with automatic monitoring equipment to achieve real-time visualization of monitoring data.In addition,the system should be added with hidden danger detection and emergency management module functions to improve the whole risk management and control system.Through the analysis and research of this paper,we can provide a scientific and systematic method for the establishment of urban rail transit construction safety risk control system for reference and reference.