The Research On SD Model Of Safety Risk Elements Transmission For Excavation Of Underground Cavern

In the field of water conservancy and hydropower construction,the excavation of underground caverns represented by underground powerhouses,main transformer rooms and tail water surge chambers has shown a “leap-forward” development trend.The excavation of these underground caverns faces problems such as large scale construction,many layers of excavation,complicated topography and geological conditions,compact layout of the caverns,difficulty in ventilation and smoke,and high clearance rate.Therefore,once a safety accident occurs in the underground cavern excavation process,it will bring huge losses,which brings serious challenges to the construction manager.In view of this,this paper comprehensively uses WBS-RBS risk identification method,MIV screening method,risk meta-transfer theory and system dynamics to construct a reasonable and effective SD model for safety risk metastasis of underground cavern excavation.Conducting a comprehensive analysis of the main risk factors for underground cavern excavation safety.Exploring the safety causal relationship of underground cavern excavation.Exploring risk meta-passing paths.Simulating the risk values of personnel,materials,equipment,technology,environment,management,and their impact on the safety risk value of underground cavern excavation.According to the risk value trend of each subsystem,the corresponding risk management and control countermeasures and suggestions are put forward to improve the efficiency of risk management and control.First,defining the concept of risk elements and risk meta-delivery.Based on the principle and method of safety risk identification for underground cavern excavation,WBS-RBS risk identification method is adopted to decompose WBS according to the underground cavern excavation process.The safety risk of underground cavern excavation is decomposed into human risk,material equipment risk,technical risk,management risk and environmental risk.And build the underground cavern excavation safety risk WBS-RBS matrix to determine the main risk elements of underground cavern excavation safety.Secondly,through the analysis of the openness,synergy and self-organization of the underground cavern excavation system.Based on the detailed description of the feasibility of using system dynamics to study the safety risk meta-transmission of underground cavern excavation,the causal relationship between the risk elements of each subsystem is analyzed.Obtain the overall causal relationship diagram of the underground cavern excavation safety system.Thirdly,based on the overall causality diagram of the underground cavern excavation safety system and the questionnaire and engineering related data and data,the MIV screening method is combined with the Vensim software function characteristics to determine the mathematical relationship of the model parameters.Construct a SD model of safety risk meta-transmission for underground cavern excavation.Finally,apply the established SD model to the engineering case.Test the validity of the model through case studies and conduct case simulation analysis.The simulation results show that the management risk subsystem has the greatest impact on the safety risk of tunnel excavation,followed by the personnel risk subsystem,the environmental risk subsystem and the technical risk subsystem.The least affected is the material equipment risk subsystem.The simulation value of each subsystem risk value is simulated,and the relevant management strategies and suggestions are given according to the simulation simulation trend graph.