Research On Construction Risk Management Of Deep Foundation Pit Of Shenwai Station Of Shenzhen Metro Line 8

In recent years,subway project is not only one of the large-scale infrastructure projects for people's livelihood,but also an inevitable trend to relieve the traffic pressure in large cities.At the same time,as an important part of subway project,the construction process quality and safety assurance of deep foundation pit engineering is particularly important.Deep foundation pit engineering is characterized by many uncertain factors,excessive accident hazards,complex surrounding environment and long period of safety risks.Risk assessment is of great significance to construction safety.Therefore,this paper carries out safety risk assessment on the construction process of deep foundation pit engineering of subway,reduces the accident probability of deep foundation pit engineering,improves the effectiveness of construction safety management,reduces the loss,provides basis for safety construction on site,and provides reference for subsequent construction process control.First of all,based on the research of construction risk management of deep foundation pit engineering in domestic and foreign subway projects,combing the existing construction risk related theories,analyzing the application scope and advantages and disadvantages of different risk identification methods,combining with the construction characteristics of deep foundation pit engineering,the WBS-RBS method is proposed to identify the construction risk factors of deep foundation pit engineering and the evaluation index set of construction risk influencing deep foundation pit engineering are determined.Secondly,the research conducts a questionnaire survey on the site management personnel and relevant experts of the deep foundation pit engineering construction of the subway,and establishes the specific construction risk evaluation index system of the deep foundation pit engineering.There are 9 construction risk evaluation indexes in the standard layer and 44 construction risk evaluation indexes in the index layer.In addition,based on the analysis of different weighting calculation methods,this paper uses the combination weighting method to calculate the comprehensive weighting of each evaluation index,so as to determine its relative importance.Then,the construction risk evaluation index value of deep foundation pit engineering is estimated by fuzzy mathematics theory,the membership function of triangle and trapezoid is constructed,the membership degree of loss degree and occurrence probability grade is calculated,and the evaluation matrix of risk grade is established.Finally,this paper combines the construction of deep foundation pit engineering of Shengwai Station of Shenzhen Metro Line 8,carries on the fuzzy comprehensive evaluationto its construction risk,and determines that its construction risk grade is three,which belongs to the controllable range,but the development unit and the construction unit still need to pay attention to and do well the prevention and monitoring measures of construction safety risk in time.The research on the construction risk management of deep foundation pit engineering in Shengwai Station of Metro Line 8,which not only helps to reduce the probability of foundation pit engineering accidents and avoid the occurrence of corresponding losses,but also provides a theoretical basis for the design and construction of deep foundation pit engineering.Furthermore,it is helpful to provide valuable reference for relevant departments to prepare relevant specifications and guidelines.