Analysis And Research Of Deep Foundation Excavation’s Influence On The Adjacent Frame Structure With Shallow Foundation

As deep foundation pit in the city are generally in the middle of the intensivebuildings, the construction environment is more complex. Some of built buildingsstructures and underground pipe network lines closed to the deep foundation pit, willmutually reinforce with the deep foundation, and influence each other. Deepfoundation pit in this environment, if not properly controlled there will be a certaindegree of impact on the surrounding environment, more seriously will affect thenormal use of adjacent buildings and underground pipelines or even lead todestruction, conventional construction techniques and the existing foundationengineering design theory is faced with severe challenges. Based on the summarizingof the current domestic and international research findings on the foundation pitdeformation control and the effect of foundation pit excavation to the surroundingenvironment, combinated the basic theory of finite element nonlinear analysis method,this paper made a further study of the effect of deep foundation pit excavation processon the adjacent shallow foundation the frame structure.In order to get the deformation law of frame structure, the retaining structure andthe surface soil in the process of deep foundation pit excavation. This paper studiesdeep foundation, retaining structure and frame structure systematically with the largegeneral-purpose finite element analysis software ANSYS. We have been consideredthe interaction between underground structure and soil in the numerical simulation ofdeep foundation pit excavation, in accordance with the construction process and theneed to simplify the calculation model during numerical simulation of deepfoundation pit excavation, the entire simulation process is divided into two phases,namely the initial stress field analysis before excavation and the construction processsimulation of deep foundation pit excavation. This program is divided into three cases,as the building from the pit10m,15m,20m, each case also was divided into twocondition, namely the cantilever pile retaining and pile-anchor retaining.First, we mainly analysis the ground soil settlement and the deformation ofretaining structure caused by the construction process, in the case of differentdistances to the adjacent frame structure by using different kinds of supportingstructure, through analysis we get the static and dynamic curves of ground surfacesubsidence and the horizontal displacement curve of retaining pile. Then simulatedand analyzed the horizontal displacement and settlement (including absolute settlement and uneven settlement) of adjacent shallow foundation frame structure, andcomparative analysis about frame deformation of different distances and differentsupport method is done, and get the deformation control inflection point2/3H (whereH is the foundation pit excavation depth). Afterwards, imposed the numericalcalculation of differences horizontal displacement and uneven settlement on framestructure as the initial displacement of the load, analyze the the internal force changesof frame structure independently, also draw that the differential deformation’sinfluence on beams and columns internal force of the frame structure beneath twolayers is more significant, the weaker impact as the higher story number of framestructure.Finally, through two cases of deep foundation engineering, analyze causes of theaccident, then we put forward the reinforcement approach based on site inspectionsurveys and deformation monitoring.