Experimental Study And Numerical Analysis Of Lateral Bearing Capacity Of Large Diameter Expanded Piles

The horizontal bearing capacity of pile group is the most common problem in pile foundation engineering,and the horizontal force analysis of pile group is less studied in pile foundation engineering.But with the continuous construction of large and complex buildings,high-rise and super high-rise buildings,the lateral load of earth pressure,wind load and seismic load on the deep foundation is also more significant.The theoretical study of the bearing characteristics of the corresponding pile foundation under horizontal load is also very important.The bottomexpanding pile has the advantages of high bearing capacity,large pile stiffness and small settlement deformation.Therefore,based on the results of the indoor model test of the lateral pile group of the expanded pile group,combining the finite element software Midas GTS NX and Abaqus which are used to establish the calculation model of the expanded pile group,we analyze the loading data,and the bearing mechanism of the lateral load of the pile group is studied.The main work of this paper is as follows:The pile foundation literature at home and abroad is reviewed and summarized.The theoretical analysis method,indoor model test method and numerical analysis method of pile foundation research are compared,and the advantages are used for reference and reference.The test parameters were designed to produce large-diameter expanded-bottom model piles and model-connected beams.The horizontal load test of the indoor model of the expanded pile group was carried out.The results of the data were summarized and analyzed,and the horizontal bearing capacity and failure characteristics of the pile group were made analysis.With the help of finite element software,the numerical model consistent with the indoor model test size is firstly established to verify the accuracy of the finite element model calculation.Then,based on the verified calculation parameters,a variety of pile foundation models are established,analyzing the horizontal load of the pile group,controlling other variables to be the same,and using the pile length and the pile spacing as the variables to analyze the horizontal bearing of the pile group.The pile foundation model with different arrangement and combination conditions is established(the straight pile and the bottom pile are staggered).Analyze the loading data and study the bearing mechanism of the horizontal piles of the piles.From the perspective of economy and technology,explore the optimal bearing capacity of the piles when the different combinations of straight piles and bottom piles are explored to conclude the optimal load bearing condition.The influence law of the horizontal bearing capacity of group piles is analyzed,mainly from the aspects of pile-soil interaction and group pile effect.Through the indoor model test,the pile-soil interaction of the pile group is simulated,and the interaction mechanism between pile and soil is analyzed.At the same time,the numerical model of various piles is established by finite element software to analyze the influence of pile length on the interaction between pile and soil.The effect is one of the important factors affecting the horizontal bearing performance of the pile foundation.Through the theoretical analysis of the pile group effect and the calculation results of the model test,the influence law of the pile group effect is summarized.