The Model Test And Numerical Analysis Of CFG Pile Composite Foundation Applied To Dredger Fill Foundation

Currently, CFG pile composite foundation technology is less used in dredger fill foundation. The bearing capacity and settlement rules of CFG pile composite foundation are closely related with the geological formation conditions.Therefore, the role sharing of pile-soil and its influencing factors, and the law of settlement, and the applicable conditions, factors, settlement rules and applicable conditions of the CFG pile composite foundation need to be experiment studied.Based on Xiamen municipal science and technology project "the Study of the Key Technology of CFG Pile Composite Foundation Applied to Dredger Fill Foundation", this paper conducted a system model test and numerical theory analysis of the above aspects. The present paper discussed the engineering properties, the force and deformation characteristics and the mechanism of composite foundation of the CFG pile composite foundation.According to the geological conditions in the field, the inner model test carried out focused on two foundation cases, the dredger fill foundation, and dredger fill foundation with sludge layer. In each case, there were experiments on the conditions of one pile, double piles and four piles. Each experiment is divided into two conditions:first, the thickness of the different cushion experiment; second, the pile composite foundation experiment. Each group of experiments measured axial force, earth pressure around of piles, composite foundation settlement. The experiments found out the bearing capacity, settlement rules of the CFG pile composite foundation and got the actual pile-soil stress ratio and pile-soil load distribution ratio range of the composite foundation. Meanwhile, the experiments gained to a reasonable cushion thickness. Experimental also verified the laws of CFG pile composite foundation with weak layer in the foundation. The influence which the weak layer has on CFG pile composite foundation can be obtained from comparing.With FLAC3D finite element analysis software, a series of numerical simulation for CFG pile composite foundation was carried out. The results of the simulation and model test were compared and the effect of the pile type, pile length, base depth, cushion and the weak layer on the CFG pile composite foundation was discussed. The paper got the corresponding results.