Study On Safety Risk Management Of Railway Tunnel Mining Method Under Complex Conditions

The railway tunnel mining method construction passes through the complex geological environment conditions,the construction scale is large,the construction period is long,and the construction participants are many,which will inevitably lead to many kinds of factors affecting the tunnel construction project in the construction stage,the risk situation is complex,and there is a greater possibility of accidents in the construction link.In the process of tunnel mining method construction,collapse,gas,water(mud)outburst and other risk accidents are prone to occur,resulting in personal and property losses.Therefore,it is of practical significance to carry out the research on the construction safety risk management and evaluation of the railway tunnel mining method.In this paper,literature research,mining method construction technology,fuzzy mathematics theory and field investigation and other means,combined with the results of the predecessors have been studied,based on the railway tunnel mining method construction stage of safety risk management assessment.Taking the Yudu No.2 tunnel project of Xingquan Railway as the research object,the safety risk assessment of railway tunnel construction is carried out.The main work and achievements are as follows:(1)According To the construction characteristics of mining method for railway tunnel,three typical emergency events indexes of collapse risk,gas risk and water(mud)gushing risk are selected as the first-level risk indexes of the probability of emergency events in tunnel construction,and 16 risk factors corresponding to the first-level indexes are selected as the second-level indexes.The risk assessment index system of mine law is jointly constructed.(2)The Fuzzy analytic hierarchy process(FAHP)and the risk consequence equivalent estimation method are used to study and establish the probability assessment model and the accident consequence assessment model for the construction of railway tunnel mining method respectively,including the use of AHP to determine the average weight value of each risk factor,the membership values of the quantitative factors in the risk factors are calculated by using the trapezoid distribution function,and the membership values of the qualitative factors in the risk factors are selected according to the fuzzy membership function proposed by Karwowski et al.Finally,the construction risk grade is determined by referring to the Interim Provisions for Risk Assessment and Management of Railway Tunnels.(3)Based on mySQL and PHP language,the development of railway tunnel mining method construction risk assessment system,to achieve the actual tunnel engineering risk assessment function.The software can also store and query accident information.The research results of risk assessment software are applied to the construction risk assessment of Yudu No.2 tunnel of Xingquan Railway.The assessment results show that the construction risk grade of the section of mileage DK36 + 070 ~ DK36 + 120 is height.(4)Based on the design model of risk assessment of mining method,the construction risk assessment of Du No.2 tunnel is carried out.The results show that the collapse risk probability of DK36 + 070 ~ DK36 + 120 tunnel in Yudu is 3,the gas risk probability is 1,the water(mud)risk probability is 4,the risk probability of tunnel construction is 4,the consequence probability is 3,and the construction risk grade is high risk.The calculation results of risk assessment are consistent with the calculation results of the risk assessment system of railway tunnel-mine construction method,which verifies the correctness of the code of the assessment system.