Study On The Performance Of Deformation Control Structure Close To Shallow Foundation Of Foundation Pit Excavation

In the building of intensive areas of conduct of the pit excavation precipitation construction,often induced adjacent existing foundation of the settlement deformation.When the deformation value exceeds a certain limit,the safety status of the building will be adversely affected.Therefore,in this paper,a type of foundation deformation control structure is designed for the combination of soil deformation induced by precipitation of foundation pit excavation.The mechanical properties and influencing factors of the structure were analyzed by the combination of indoor model experiment and simulation analysis.The main research results are as follows:(1)Based on the deformation of adjacent existing foundation and its deformation inducing factors,a type of foundation deformation control structure is designed.The structure can be used for dynamic control and pressure compensation for the possible deformation of the shallow foundation in horizontally and vertically.From the structural characteristics and stress mechanism,the structure can effectively prevent and control the deformation.(2)Based on the actual situation of the foundation deformation induced by the excavation of the foundation pit and the actual situation of the design structure,a simplified indoor experimental model is established.The pressure compensation value,the earth pressure and the foundation deformation of the deformation control structure during the excavation of the foundation pit are simulated.According to the results of model test,the structure proposed in this paper can effectively control the deformation of adjacent existing foundation induced by foundation pit excavation.By analyzing the experiment results of support displacement and earth pressure,the change of force and displacement of soil and supporting structure during excavation of foundation pit is clarified,which reveals the correlation between the performance of the basic deformation control structure and the change of the foundation displacement and the stress of the supporting structure.(3)Based on the indoor model test,ABAQUS finite element software was used to establish the simulation analysis model.The mechanical characteristics of the structure,the displacement of the surrounding soil and the distribution of stress are analyzed.The segregation properties and the response of the structure are analyzed when the factors such as the embedded depth of foundation,the groundwater level,the support stiffnessand the soil parameters are changed.From the comparative analysis,the soil parameters have the greatest influence on the structural performance,followed by groundwater level,the influence of foundation embedded depth is relatively small.