Research On Safety Risk Management Of Construction Work Of Tower Crane Group Based On System Dynamics

With the increasing number of construction engineering projects,the construction area and scale of engineering projects are getting larger and larger,and the use of multiple tower cranes in engineering projects is becoming more and more widespread.The fatality rate of tower crane accidents is the highest among construction safety accidents.The three-dimensional cross operation of multiple tower cranes is different from the single operation,which has higher risks,and puts stricter requirements on the safety management of the tower group operation.How to ensure the effective control of the safety of the three-dimensional cross operation of multiple tower cranes during construction is of great significance.Based on extensive literature reading and case analysis,this paper analyzes the safety risk factors of construction tower group operations,and for the first time combines the system dynamics(SD)theory with the tower group operation safety risk research.Mainly considering the risk factors that may affect the safety of the tower construction process.Considering the safety of construction tower group operation as a whole system,divides five subsystems of personnel,tower group equipment,environment,management and technology.The system dynamic causality diagram and flow diagram of the safety risk of the construction tower group are constructed,and the safety level trend of the tower group operation risk system is obtained through simulation.On the basis of the divided 5 subsystems,35 internal factors of the system were identified,and the combination of G1 method and entropy weight method was used to determine the weights of 35 risk factors and 5 subsystems.The system dynamics simulation software Vensim-PLE was used to construct a feedback model for the safety risk identification of the construction tower group.The causal relationship between the factors in the system was determined.Based on the risk identification feedback model,SD flow diagrams were drawn and the tower group operation risk was simulated.The safety level of the system,and by changing the single-factor variable method,the initial value of the internal factors of each subsystem is reduced by 0.05 each time,and the internal factors of only one subsystem are changed at a time to simulate the risk of personnel to the safety of the tower group operation.The degree of impact is the largest,followed by environmental risks,tower group equipment risks,management risks,and technical risks.The method of changing the single factor variable for the personnel risk subsystem was simulated to obtain the driver's business level has the greatest impact on the safety of the tower group,followed by the technical personnel's ability,the weakness of personnel safety awareness,the signaling business level,the driver's physical and mental quality,Competence and continuous working hours of safety management personnel.Finally,combined with actual engineering cases,the established model was used to simulate the safety level of tower operations in actual engineering projects to verify the validity and applicability of the model.Based on the simulation results and actual case analysis,control measures for the security risks of tower operations are proposed.In combination with smart construction,BIM technology and the introduction of the Internet information system to strengthen the risk control of tower group operation safety provides a certain reference value for future tower group operation safety management.