Study On The Risk Assessment Of Construction Safety Of Urban Underground Engineering

With the development of the city and the accelerated process of urbanization,more and more urban problems are beginning to appear.Urban problems such as traffic congestion,environmental pollution,green atrophy and urban flood and waterlogging are restricting the development of cities,and the problem of urban space shortage is becoming more and more serious.However,the development of urban underground space is conducive to easing urban traffic,improving urban environment,increasing the function of cities and alleviating the tension of urban land.As a result,more and more cities begin to develop and use urban underground space.Subway,underground commercial body,underground parking lot,underground tunnel,underground tunnel,underground civil air defense project and other urban underground projects have sprung up like bamboo shoots after the rain.However,the scale of urban underground works will increase,and the safety risks will also increase.First,the paper analyzes the development status of the safety risk management of urban underground engineering construction at home and abroad,drawing on the management mode of foreign developed countries and combining with the current development status of our country,analyzes the problems and shortcomings of the construction safety management of urban underground engineering in our country.Lacking of safety management methods and outdated safety assessment methods are the main problems encountered in the construction safety management of urban underground works in China.Then,by comparing several methods applied to safety evaluation,analyzed the advantages and disadvantages of each one and their applicable scope,we selected the fuzzy comprehensive analysis method which can better reflect the real state of the safety risk as the evaluation method for the safety risk of urban underground engineering construction,and selected Analytic hierarchy process(AHP)to determine the weight of the evaluation index.Finally,Comprehensive construction safety risk accident of underground engineering in China in recent ten years,the main risk factors in the construction process of urban underground engineering are calculated through the theory of accident inversion,and the risk factors are divided according to the theory of "4M1E" accident factor,and 26 factors that affect the construction of urban underground engineering are selected as evaluation indicators and other relevant standards are consulted and experts’ opinions are consulted to determine the scoring criteria.At the same time,based on the inadequacy of fuzzy comprehensive evaluation method and the advantages of cloud model,the fuzzy comprehensive evaluation model of fuzzy comprehensive evaluation and cloud model improvement is constructed respectively.In combination with relevant cases,it is proved that the latter can not only find the potential high risk factors,but also the evaluation results are more intuitive and accurate,It provides some references and guidance for risk assessment and control of urban underground engineering construction safety.