Risk Evaluation And Control Of Water Diversion Tunnel During Construction Period

With the acceleration of socialization process,tunnel engineering has been applied and developed systematically.The increase of the number of tunnel construction,the expansion of scale,the risk probability of tunnel construction period doubled,resulting in casualties and economic losses.Therefore,tunnel risk assessment and risk control are of great significance.In this paper,the current situation of Tunnel Risk Management at home and abroad is briefly introduced,and then the related concepts and methods of risk management in the construction period of diversion tunnel are studied.According to the order of risk identification,risk assessment,risk assessment and risk control,the risk management of the diversion tunnel of the Han,Wei and Wei River is carried out in accordance with the actual risk.Taking the three section water diversion tunnel of Hanji Wei Huang River as the support of the project,the risk factors of construction period are explored and the risk factors of construction period are summed up.Through the expert experience method,the risks faced by the constructor in the construction process are summarized,the risk sources are analyzed,the risk system system is established,and the Pareto's analytic hierarchy process and the grey system are used respectively.The weights of 8 risk factors for the risk identification of the diversion tunnel are analyzed.The analytic hierarchy process(AHP)analyzes the relative weight of the risk factors and sorts,then relies on the loss expectation sorting and Pareto map,establishes the risk evaluation system,and determines the main risk,secondary risk and general risk of the construction period of the tunnel,which is based on the grey system theory,which is based on the analytic hierarchy process(A).Then we refined the risk of A layer to B level,and calculated the grey level statistics of the two factors respectively,and got the weight of risk factors.Through the comparison of the two methods,the results are consistent,and the main risk factors are the same: the landslide caused by bad geology,the tunnel(surge)water,the instability of the surrounding rock is the main risk in the construction period of the three section of the water diversion tunnel of the Yellow River,and then the construction technology for the landslide is determined: that is to know the contrast design and the actual geology.In order to strengthen the advance geological forecast and direct work in the early stage of construction,we should change the construction method in time and prevent the collapse while preventing the collapse.It is necessary to prevent and drain the water at the same time,to prevent the water from the sudden(surge)water,that is to estimate the water inflow in the tunnel construction,use the advance geological pre report,collect the information in time to adjust the construction.The plan is to strengthen supporting measures and block and cut off deep water in order to achieve the purpose of seepage prevention.Finally,through monitoring and measuring technical means to ensure the reasonable control of the quality of the project,the construction safety progress target,and so on,to ensure the safety of the tunnel construction,to achieve the goal of tunnel safety.Through the risk assessment and control of the construction period of the water diversion tunnel,this paper can effectively analyze the risk sources in the construction period,strengthen the control and management,reduce the risk in the construction period,and have a good reference for similar engineering examples.