Research On Risk Assessment Of Gas Tunnel Construction Based On Combination Weighting Method

With the continuous development and growth of our country,the scale of transportation engineering construction is also becoming increasingly large.In the southwestern region of China,tunnels,as important nodes connecting the transportation network,demonstrate their unique role even more.Among numerous tunnels with different geological conditions,the construction of gas tunnels is prone to frequent safety production accidents due to its uncertainty,high risk,and lack of management experience.This article extensively collects,summarizes,and analyzes relevant literature and journals on gas tunnel construction and risk assessment both domestically and internationally.It conducts in-depth research on gas tunnel construction from a risk perspective,and uses the pre hazard analysis method based on human activity system models to divide gas tunnel construction risks into three levels: execution level,quality level,and management level,and visually represents them using causal diagrams,On this basis,a risk assessment index system for gas tunnel construction has been established.A risk assessment model for gas tunnel construction was established using the G1 method-COWA combined weighting method and fuzzy comprehensive evaluation methods.Based on the Yan’e Mountain Tunnel Project of the Wuzhen Expressway in Chongqing,the above indicator system and evaluation model are specifically constructed and analyzed in depth.Based on the evaluation results,risk control measures for the construction of the Yan’e Mountain Tunnel are formulated,and the following research work is mainly completed:(1)By collecting literature on risk assessment of gas tunnels both domestically and internationally,learning and researching methods for risk assessment,using human activity system models and the idea of pre hazard analysis,the construction risk of gas tunnels is divided into three subsystems: execution layer,quality layer,and management layer.Each subsystem is further divided into corresponding factor layer and indicator layer,and the risks of each layer are identified and summarized,and then depicted using fishbone diagram method,Finally,a risk assessment index system for gas tunnel construction was established.(2)Based on the characteristics and risk characteristics and types of gas tunnel construction,and considering the complexity of consistency testing using methods such as Analytic Hierarchy Process and the inability to avoid the influence of subjective factors and extreme values,a gas tunnel construction risk assessment model that meets the risk assessment requirements is proposed by combining the G1 COWA combination weighting method and fuzzy comprehensive evaluation method.(3)Taking the Yan’eshan Tunnel of Wuzhen Expressway in Chongqing as an engineering example carrier,the above indicator system and evaluation model are applied to identify,analyze,evaluate and propose risk control measures for the Yan’eshan Tunnel.The evaluation results are compared and verified with the accident tree evaluation results established based on the actual construction process of the tunnel,ensuring the practicality and reliability of the system analysis.