| With the rapid development of urban construction,high-rise buildings mushroomed constantly emerging,the excavation area of deep foundation pit is more and more large,and the excavation depth is also increasing.Therefore,choosing a reasonable and scientific foundation pit support scheme becomes the basis of ensuring.Pit engineering quality and safety,stability is very important part.In the process of excavation,some problems around the project should be taken into consideration at the same time,such as the settlement of the surrounding ground,the settlement of the building,the settlement of the road pipeline and the horizontal displacement of the retaining pile.In recent years,due to improper excavation of the foundation pit,unreasonable selection of the retaining structure,instability of the foundation pit caused by deviations of on-site monitoring data and so on,it is reasonable to choose and design the foundation pit support plan In the process of excavation,the deformation law and force characteristics of the retaining structure and the surface subsidence of the foundation pit can avoid the serious loss and safety accident caused by the stability of the foundation pit being damaged in the construction of the foundation pit.Based on the study of the deformation mechanism and failure mode of deep foundation pit,the paper analyzes the main factors which affect the stability of deep foundation pit.Based on the project of cotton seven plant in Shijiazhuang City,the paper analyzes the horizontal displacement,surface settlement,The variation of soil bulge was simulated by FLAC-3D software to simulate the influence of surrounding ground surface settlement and the horizontal displacement of retaining pile and soil bulge at the bottom of pit during the step-by-step excavation of foundation pit.The simulation results and monitoring results By contrast analysis,the deformation law of deep foundation pit is obtained.Finally,the stress stability method was used to study the overall stability safety factor,anti-overturning stability safety factor and anti-swelling stability safety factor of foundation pit excavation.The stability of the deep foundation pit supporting structure was verified.It provides some design basis for the excavation and support of similar projects in the future,which will have some guidance and reference significance. |
