Research On The Safety Risk Assessment And Control Of Deep-foundation Pit Excavation At Xuefu Street Dongkou Station In T City Metro Line 1

Since the reform and opening up to the outside world in 1978,the economy has been booming in China,and the urban population has been increasing.In order to effectively alleviate the traffic pressure in the metropolitan life circle,the subway has become the first choice for many citizens to travel because of its fast,punctual,safe,large passenger volume and other advantages.The traffic along the subway is often heavy,the pipelines are densely distributed,the buildings are numerous,and the surrounding environment is complex,which brings more and more uncertain factors to the subway construction,and the safety risks are also growing.A series of safety accidents,such as surface settlement,slope instability,foundation pit collapse,water gushing and sand gushing,remind us that the safety risk management of deep foundation pit excavation in subway stations has a long way to go.This paper chooses the deep foundation pit excavation at Xuefu Street Dongkou Station of the T-city Metro Line 1 as the actual research object.Based on the WBS-RBS analysis,the list of risk sources in different processes of the subway station is obtained.Using expert investigation method and fuzzy analytic hierarchy process,the risk identification judgment matrix of each engineering risk factor is constructed,the corresponding list of risk sources is listed,and the surrounding environmental factors The potential risks existing in the factors of foundation pit construction and the professional quality of the construction personnel were determined.It was found that the risk factors of the surrounding environment during the construction process of the project were Level I extremely high risks,and the risk level of deep foundation pit collapse,instability and landslide was Level II high risks.In view of high risk factors,scientific and reasonable supervision measures should be formulated.During the construction process,vigilance should be enhanced and patrol monitoring should be strengthened to ensure that the safety risks of deep foundation pit construction in subway stations are reduced.Through this study,in cities with complex geological environment,the risk factors of subway deep foundation pit construction safety have been comprehensively analyzed and combed,and the corresponding risk assessment model has been established.Combined with the construction cases,a relatively complete set of safety risk response strategies in the construction process of subway deep foundation pit has been formed,which has practical and theoretical significance for ensuring the smooth construction of subway projects in T City,it also provides a certain reference value for the subsequent construction of similar subway stations.