Construction Safety Risk Assessment Of Underground Space Engineering Based On Combined Weighting Method-cloud Model

As the pace of urban construction continues to accelerate,more and more attention is paid to the use of underground space.At present,my country’s construction industry has made great progress,and construction accidents have generally declined.However,due to the difference in economic scale and project scale,safety risk management is still facing great challenges,especially underground construction still has a certain degree of safety Hidden dangers.To avoid accidents and disasters in underground space engineering construction,scientific and reasonable safety risk assessment is carried out for possible risk factors in construction.In this paper,the influencing factors of underground space engineering construction risk are analyzed from five aspects: accident data statistics,typical accident fishbone diagram analysis,accident risk direction analysis,literature investigation and research,and the characteristics of the project itself.According to the results of construction risk analysis and the theory of man-machine loop management,the evaluation index system of underground space engineering construction safety risk is constructed,and four primary index risks and 16 secondary index factors are put forward.On the basis of the theory of underground space engineering construction safety risk assessment,the subjective and objective weights of risk assessment indicators are determined by AHP and entropy weight method respectively,and the combined weights are determined by multiplication synthesis method.Based on the theory of cloud model,the safety risk of underground space engineering construction is divided into five grades,and the index risk grade standard is put forward,and the safety risk assessment model of underground space engineering construction based on combination weighting method and cloud model is constructed.Finally,the model is applied to the underground space construction of a large-scale experimental building,and the comprehensive cloud characteristic value is calculated by the combination of the characteristic value of the index cloud and the combined weight value.The comparison chart between the index risk cloud and the standard cloud is formed by using the conventional cloud generator,so as to show the risk status of the evaluation indexes at all levels and determine the overall risk level of the underground space construction project of the large-scale experimental building.The results show that the risk level of the underground space construction of this large-scale experimental building is "general risk",and the risk control measures and preventive measures are put forward for the risk factors with high influence and construction accidents with high frequency by adopting the priority principle.The evaluation results are basically consistent with the engineering practice,which proves that this method has good feasibility and applicability,and provides a new method for the safety risk control of underground space engineering construction.