Construction Management Research On Deep And Large Excavation With Large Diameter Double Ring Brace In Soft Soil Area

Both Tianjin and Shanghai are located in typical soft soil area,where the engineering geology and hydrology geology contion is poor,so the deep and large foundation pit projects in urban district have a lot of technology and management problems.Relying on two foundation pit progects,Tianjin Lujiazui Squere project and Shanghai Hongqiao 08 Block D13 project,the article devote to research on foundation pit supporting technical management,foundation pit earthwork process management and foundation pit construction safety emergency management according to the supporting system of scheme selection,earthwork excavation process,and emergency safety plan,to realize the security,quality,schedule and economic goal of the projet.The main research content and results include:(1)According to the techno-economic analysis on supporting structure scheme,include the contrastive analysis of partition or no partition,line or ring-shaped brace system,Triaxial Soil-cement Mixing pile or Trench cutting Re-mixing Deep wall waterproof curtain,research and select the suitable foundation pit support system.The ring-shaped supporting system(?=116m/150m)can make most of concrete compressive strength,and form wide earth cutting speace.TRD waterproof curtain stirs well,and can avoid bad connetion,so the effect of preventing water is much better.(2)According to the conparition and analysis of the bench and auger-type on center island Earthwork excavation process,to research the schedule management of earthwork engineering of foundation pit from the excavation in blocks,unearthed efficiency and support formition.In the construction of foundation pite,take full advantage of the line and corner brace's local system balance in two ring-shaped supporting systems,partical earch excavation conbine with partical baece constrction,adopt the the centre island auger-type earth excavation,complete the supporting system as soon as possible.Make the most of tau-effect,and complete the supporting system in the shortest possible time after excavation,to make the foundation pit and surrounding environment's deformation under control.(3)According to the theoretical research and practical on foundation pit safty,fire-fighting,public security and emergency management,establish the safety production assurance system of group,company and project department trinity.Based on the assurance system,formulate specific and pointed security,fire-fighting,public security and emergency management measure,plan contingency plan,and establish emergency organization,give full play to all aspects of resources,and provide safety management organization and system guarantee.