The Test Research On Interaction Of Pile And Soil With Different Structural Form Between Pile Top And Foundation

Both composite pile foundation and rigid composite foundation can accomplish bearing super structure load by pile and soil. There are some difference in interaction of pile and soil because of different structural form between pile top and foundation in composite pile foundation and rigid pile composite foundation. Along with composite pile foundation and rigid pile composite foundation having been in great use in high building with raft foundation and foundation design method according to foundation settlement having been further adopted, the influence of different structural form between pile top and foundation on foundation work behavior have becomed people's hot spot. It has theoretical and practical meaning to research pile and soil interaction between pile top and foundation in different structural form.Through big scale model test in site, this paper researched the work behavior of composite pile foundation, rigid pile composite foundation and nonuniform arrangement rigid pile composite foundation in high building raft foundation with super structure under nonuniform load on raft foundation. The work behavior of composite pile foundation with space between pile top and foundation was also researched in rigid foundation form under uniform load. The settlements were measured on raft foundation(or rigid load board),different depth subgrade under raft foundation(or rigid load board) and different depth subgrade beside raft foundation(or rigid load board) under different load level. The axial force of pile in different depth and soil stress under foundation were measured under different load level, too. It was analyzed the influence of raft total settlement, differential settlement, pile-soil stress distribution, pile-soil load transition, pile-soil load sharing scale and the space between pile top and foundation on the work behavior of composite pile foundation. Comparing the work behavior of composite pile foundation and rigid pile composite foundation, nonuniform arrangement rigid pile composite foundation and composite pile foundation with space between pile top and foundation, the pile-soil interaction of different structural form of pile top and foundation were researched and the laws of pile-soil interaction were obtained from composite pile foundation and rigid pile composite foundation, nonuniform arrangement rigid pile composite foundation and composite pile foundation with space between pile top and foundation. The design method was put forward on composite pile foundation with space between pile top and foundation. The result of settlement using design method given in this paper was in good correspondence with settlement result of model test measured in site and three dimension finite element analyzed.