Supporting Design And Numerical Simulation Study Of Double-row Piles On Deep Foundation Pit In Guangzhou

During the excavation of foundation pit,the original stress distribution of surrounding soil will be changed,this will cause displacement of side wall of foundation pit,heave of bottom pit,and it will also affect the surrounding buildings,roads and pipelines,so it is very important to study the deformation of foundation pit excavation and numerical simulation analysis.Based on the calculation theory of double-row piles support system,this paper takes a foundation pit project in Guangzhou city as an example,Firstly,the design and calculation are carried out by using Lizheng7.0 software,then using Midas GTS NX to conduct three-dimensional simulation analysis of foundation pit excavation and double-row piles support,finally,comparing and analyzing the simulation,calculation of Lizheng7.0 software and field monitoring results to verify the rationality of the model.In this paper,the main contents and achievements of study are as follows:(1)This paper summarizes the characteristics,advantages and disadvantages of the double-row piles support structure,and briefly introduces the analysis and calculation theory and model of the double-row piles support structure.(2)In this paper,the software of Lizheng7.0 software deep foundation pit is used to design the support scheme and check the stability of the scheme.(3)According to the relevant data of the foundation pit project,selecting appropriate constitutive model and parameters,this paper uses Midas GTS software to establish a numerical model to simulate the excavation process of foundation pit,and analyses the deformation law of foundation pit and double-row piles supporting structure.(4)The results of numerical simulation and rationalization calculation are compared with those of surface settlement,surrounding environment settlement,horizontal displacement of pile top and deep horizontal displacement of pile body,which verifies the feasibility of the support scheme and the correctness of the numerical model.(5)Using Midas GTS software to simulate the double-row piles support structure with different row spacing,pile spacing and pile length,analyzing the change rule of bending moment and displacement of front and back row piles under different conditions,and obtaining the reasonable range of row spacing,pile spacing and pile length.The support design and numerical simulation analysis of a deep foundation pit project in Guangzhou can be used as a reference for similar projects.