Study On Deformation Of Pile Anchor Foundation Pit Considering The Influence Of Pile Foundation Base

The cost of foundation pit could be properly considered on the premise that the safety of foundation pit is guaranteed; besides, this has always been a goal for design and construction personnel to achieve equilibrium between these two aspects. To control the deformation of foundation pit, the geological conditions of slope hydrology, support pattern, form of construction work and other factors are usually taken into consideration as the major factors. In addition, to set up foundation pit with pile foundation to the basement, the impact that pile foundation brings to deformation of foundation pit can’t be neglected, either. Based on the current pile foundation, the maximum role of the pile foundation could be realized through studying the influence mechanism that pile foundation brings to deformation of foundation pit and optimization of the pile foundation layout. This is also one of the major approaches to save the cost of the foundation pit.This paper is referenced with the example from K0+420 section excavation at a U-type slot for new road reconstruction project in Shenzhen Northern Railway Station; besides, MIDAS-GTS is utilized to analyze the impact that the basement uplift pile brings to deformation of foundation pit. Based on this, a comparative research is conducted for the layout of the basement uplift pile and a rational layout suggestion, which could provide a theory evidence for the similar foundation pit construction project like design of pile foundation is put forward accordingly. Results from the research show as below:(1) Uplift pile set up to basement has a certain impact to cause rise at the basement center, land movement around the basement and fender post deformation; while it has no obvious impact to land movement at the top of the foundation pit and sedimentation;(2) The basement uplift pile only has impact to the deformation of foundation pit within a certain depth range in the initial excavation stage; meanwhile, its impact could be neglected when the excavation is surpassed over a certain depth range;(3) The impact that the basement uplift pile spacing brings to the deformation of foundation pit is greater than the impact that pile length brings to the foundation pit. For such construction project, it is suggested to reduce pile length and pile spacing; in addition, short pile with dense layout is designed to have a better effect for uplift pile to control deformation of foundation pit.