Risk Management For Tunnel Construction Based On System Dynamics

With the rapid development of tunnel engineering, more and more people paid attention to the construction risks, because it will not only lead to huge economic losses, and workers’ lives will be threatened once the safety of the construction stage is destroyed.Due to the complexity of tunnel system and more risk events, risk system was divided into collapse, water bursting, gas explosion and rockburst four subsystems with systems analysis method. The paper introduced system dynamics theory and method to reveal the causal relationship of complex factors in each subsystem respectively, build simulation models conforming to reality of tunnels in our country, and observed dynamic behavior of these factors, risk level quantitatively. Then simulate risk level of tunnel construction, explore and analysis different decision-making plans through empirical case studies, which could directly predict the future risk, provide theoretical guidance for safety management, also helps to improve the scientific and foreseeability of safety management decision in tunnel construction.The main research work and content in this paper are as follows:First, identify risk research problems in tunnel construction through summing up the tunnel construction safety situation in China, tunnel safety risk management present situation at home and abroad, tunnel engineering risk management theory, etc.Second, this paper uses the improved WBS-RBS risk analysis method to identify tunnel construction risk factors, establishes the tunnel construction risk factor system and analyzes the relationship between each risk factor.Third, draw the causality diagram based on analysis of causal relationship applying the theory and method of system dynamics, and establish stream flow rate, variable sets and a flow chart according to the causality diagram, then system dynamics model is completed.Forth, taking Longquan Mountain Tunnel for Passenger Line from Chengdu to Chongqing as an example, uses VENSIM PLE software to forecast the tunnel construction system risk level, and the corresponding risk prevention measures are proposed according to the simulation results.This study aims to use the idea of system dynamics to research the tunnel construction risk management problems, which put forward a new research idea to improve the efficiency of the tunnel construction risk management, reduce the management cost.