Study On The Construction Influences Of Shield Tunnel Excavation To The Around Piles

Stratum deformation caused by the city subway tunnel excavation over a certain range,will have great influence from the pile foundation of surrounding buildings, so as to affect thenormal use. In this paper, on the basis of theoretical analysis, combining with a subway shieldtunnel crossing around pile foundation engineering example, based on the finite elementsoftware MIDAS/GTS, use the method of numerical simulation, consider tunnel adjacent sideof the different position of the pile foundation and the tunnel vault at different positions, aswell as the different construction stage of pile foundation deformation and axial force of thechange, and consider the change law of different location of the pile foundation on differentexcavation footage. In the final analysis the displacement change of tunnel excavation onadjacent pile group.Pile foundation is in the certain position of the tunnel adjacent side and above tunnelvault, tunnel excavation effect on deformation of the pile increases with the increase ofexcavation; Pile foundation is in the different position of the tunnel adjacent side and abovetunnel vault, As the spacing between tunnel and pile increasing, the excavation effect on thepile foundation is decreasing. And draws the curve of the basic shaft force and piledisplacement with the spacing changed between tunnel and pile foundation.The excavationfootage is greater, the disturbance of soil is larger, Therefore, the displacement of the pilefoundation subsidence value is greater, but small will affect project construction schedule,takes suggestions that according to the actual situation,then reasonable adjust excavationprogress. Tunnel excavation influence on pile group，the nearly pile deformation than the far,with the same location of the deformation of single pile in pile group less than thedeformation of the single pile. Finally proposed the subway tunnel construction control measures of the impact on thepile, grouting reinforcement, reinforcing pile and pile foundation underpinning are effectivemeasures to control the deformation of pile foundation.