Deformation Monitoring And Numerical Simulation Analysis Of Composite Soil Nailing Wall Retaining And Protecting Structure

Based on the soil nailing wall + prestressed anchor + water cut curtain composite soil nail wall support as the background,combined with the monitoring data of a sewage treatment station foundation pit case in Beijing,the displacement deformation of composite soil nail wall slope is taken as the research object.Using FLAC3 D finite difference software for numerical simulation analysis,mainly to carry out the following work:(1)Summarize and analyze the research status of soil nailing wall and composite soil nailing wall which are widely used in foundation pit engineering at home and abroad,and bring out the problems faced by the current composite soil nailing wall in engineering application and the future development direction.(2)The mechanism of soil nails,anchors and water curtains in composite soil nailing wall retaining structure is briefly described.The overall stability checking formula of the composite soil nailing wall supporting structure is listed.(3)The engineering background,design and construction plan and monitoring plan of the foundation pit case of the sewage treatment station are introduced in detail.The foundation pit monitoring plan includes the horizontal displacement of the slope top,the vertical displacement of the slope top,the surrounding surface and pipeline displacement,and the analysis of the monitoring data.The monitoring results show that the composite soil nailing wall has great advantages in limiting the deformation displacement and shortening the construction period under the premise of ensuring the safety and economy of the foundation pit.(4)The steps of establishing and solving the FLAC3 D finite difference software model are described.The deformation displacement of the slope top and the axial force of the soil nail and anchor are simulated in the step-by-step excavation support of the foundation pit.The measured data and the simulation results show that the two are far apart,and the simulated values only provide qualitative reference and analysis for the deformation of excavations.