Study On The Influence Of Deep Foundation Pit Excavation On Soil Deformation

Based on the impact of deep foundation pit excavation to the adjacent history styleconstruction, the article analyzed monitoring data on supporting system and the surroundingstrata deformation caused by foundation pit excavation at jinwan square. FLAC3D was adoptedto analyze the displacement of the retaining wall, the supporting axial force, the displacement ofpiles on the top and the displacement of soil near the pit digging to the different depth. Finally,the simulation results compared with the measured ones and we predicted the maximumhorizontal displacement to historic buildings (the former French barracks) at the foundation pitsouth.Research results show that:(1)end of excavation, the maximum horizontal displacement ofretaining wall in the south of side is106.2mm, in depth from surface to9m. During the processof excavation, support is given priority to axial pressure, the maximum supporting axis stress is14230KN, appearing on the east-west Z1-13. The influence of the surface subsidence is about40m, about two times the depth of foundation pit excavation, and the maximum surfacesubsidence is12.3mm in the south of pit side, the distance is7m from the monitoring point tothe edge of pit.(2)spatiality and integrity is the characteristic to the deformation. The law ofhorizontal displacement field on deep soil is similar to the law of the retaining wall deformation.The wall and pile have the phenomenon, sink before uplift under the action of vertical unloadingand uplifts.(3) by contrast, we find the simulation law was chose to the test one, and thesimulation values were choses to the monitoring ones. Analysis results:(4) we can predictaccording to the simulated values: digging to the bottom, the horizontal displacement to historicbuildings in the south of the foundation pit is12.1mm in surface and the maximum horizontaldisplacement is20.2mm, in depth from surface to4m. I think it has a certain effect to historicbuildings (the former French barracks) caused by foundation pit excavation at jinwan squareaccording to the existing literature.We can use such analysis results for guiding engineering safety construction and protectingthe adjacent historic building.