Research On Construction Safety Risk Management Of Prefabricated Open-cut Subway Station At H Station Of QD Metro Line 6

With the rapid development of our economy and the continuous expansion of the city scale,urban rail transit,with its advantages such as high efficiency,safety,high transport capacity,low energy consumption,light pollution,has gradually become a major traffic force in the domestic cities.In subway engineering construction,the traditional cast-in-place concrete construction method has been inconsistent with the current national "double carbon" strategy and the trend of industrialization transformation of construction industry because of its shortcomings such as long construction period,large pollution and large labor force.The prefabricated structure has the characteristics of short construction period,low pollution and high quality,and has been gradually applied in the field of subway construction.At the same time,construction safety is a prerequisite to ensure the smooth progress of project construction,but the application of prefabricated technology in domestic subway engineering is still in its infancy,and the safety risk management of prefabricated subway station is not perfect.Therefore,it is increasingly important to carry out research on the safety management of the application of prefabricated technology in subway engineering and improve the safety management system.Combined with the actual situation of H station project of QD Metro Line 6,this paper carries out a research on safety risk management of open-cut prefabricated subway stations through risk management theory for risk identification and evaluation.The main research contents are as follows:(1)Through systematic review of relevant literature and research results,this paper introduces in detail the construction technology of prefabrication,transportation and assembly of prefabricated subway stations,expounds the characteristics and application scope of currently commonly used safety risk identification and evaluation methods,analyzes the risks in the construction process of prefabricated subway stations,and provides sufficient conditions for subsequent research.(2)The work structure is decomposed from the five stages of pre-construction preparation,component prefabrication construction,station foundation pit excavation,station assembly preparation and Station structure assembly.Then,based on the 4M1 E theory,The risk structure was decomposed from five aspects: construction personnel factor,construction equipment factor,construction material factor,construction technology factor and surrounding environment factor.The WBS-RBS method was used to identify the construction safety risk factors of prefabricated open-cut subway station,and the safety risk identification matrix was constructed to form the construction risk list of prefabricated open-cut subway station.(3)After analyzing the characteristics and application scope of various commonly used security risk assessment methods,expert scoring and analytic hierarchy process are selected to determine the weight of each risk element,and then the risk rating set is established to conduct fuzzy comprehensive evaluation and judgment analysis,and the risk levels of each index layer and criterion layer are obtained successively.(4)Taking H Station of QD Metro Line 6 as an example,the construction safety risk management research is carried out.The research results show that the risk level of this project is major risk,in which the factors of construction personnel,construction equipment and construction technology are major risks,and the factors of construction materials and surrounding environment are major risks.Then according to the research situation,the corresponding risk control measures are put forward in the aspects of safety consciousness,safety management system,large equipment control,small machinery control,embedded parts quality management,spreader quality management,foundation pit design management,station component design and surrounding environment.Through effective management and control,the construction safety and efficient promotion of the project were realized,the construction process was stable and orderly,and no safety accidents occurred,which provided experience for the subsequent construction of prefabricated open-cut subway station.This paper systematically analyzes and identifies the risk factors of prefabricated open-cut subway station construction,builds a risk assessment model based on analytic hierarchy process and fuzzy comprehensive evaluation method,and carries out analysis and verification in practical engineering cases,further enriching the construction safety risk assessment research content of large underground prefabricated structure buildings.It has some reference value for the risk management of prefabricated station construction under similar conditions in the future.