Study On Construction Risk Management Of Baimashan Tunnel On Chong-Qian Railway

In recent years,the construction of China’s railway transport infrastructure has developed rapidly.With the construction of high-speed railway,intercity railway,suburban railway,and the implementation of the strategy of "Western Development",the length of railway tunnels in southwest China has increased on a large scale,and the geological complexity of tunnels has increased.Tunnel engineering has multiple complex risk factors and is relatively hidden.During the tunnel construction stage,the possibility of accidents is high,and the resulting losses are often catastrophic.Therefore,in order to ensure the construction safety during the tunnel construction phase,it is necessary to conduct systematic and in-depth research on risk management in railway tunnel construction.This article takes the Baimashan Tunnel of the Chongqing Guizhou Railway as the research object,and studies the risks during the construction phase of the Baimashan Tunnel.The main research content and conclusions are as follows:(1)The connotation of railway tunnel risk was introduced,and the mechanism of railway tunnel risk formation was explored.The objectives,content,and process of construction risk management were clarified.Based on current standards and relevant literature achievements,tunnel construction risks were divided into four levels:extremely high,high,medium,and low.Different acceptance criteria and response measures were proposed for different risk levels.(2)Through statistical analysis of 75 cases of mountain tunnel construction safety accidents in China from 2010 to 2022,the time,space,type,and cause characteristics of mountain tunnel construction safety accidents were obtained;Based on existing research results and expert investigation methods,a risk factor checklist for tunnel construction was obtained,and the concept of a "person object environment technology management" system was proposed.Based on this system,a risk factor system for tunnel construction was established.(3)A risk assessment index system for Baimashan Tunnel was established based on the engineering characteristics and accident risk factors system of Baimashan Tunnel.The relative weights of the construction risk assessment index system for Baimashan Tunnel were calculated using the entropy weight method;By using the fuzzy comprehensive evaluation method to evaluate the probability of the construction risk of the Baimashan Tunnel,the probability level is obtained.By estimating the consequence equivalent,the consequence loss level is obtained,and the risk level of the entire construction of the Baimashan Tunnel is obtained by coupling the probability level with the consequence loss level.(4)Corresponding control measures have been developed for the human and management risks,material risks,environmental risks,and technical risks of the Baimashan Tunnel.A dynamic monitoring system for the construction risks of the Baimashan Tunnel has been established,and the content and process of risk monitoring have been clarified.The monitoring,warning,and control standards for deformation and gas in the tunnel have been determined.