Working Mechanism Of Cushion To The CFG Pile Composition Foundation And Research Of The Deformation-based Control Theory Design

The CFG pile composition foundation is composed of three parts, that is, CFG pile, pile-soil and cushion, it has such characteristics of high-speed engineering, short-period project, easy quality control and economically. At present, it has being widely used.The paper focuses on the fundamental principal of composite foundation and the working mechanism of CFG pile composite foundation. Besides, the effect of cushion to the composite foundation is analyzed in the paper. And according to the load testing, both the thickness and rigidity of the cushion have effect on the pile-soil stress ratio, either the excessively thinness or over thick load capacity can not function well. To the effect of cushion on the pile-soil stress ration, based on the finite element method theory, the paper establishes the single-pile composite foundation model, analysis the value, compare the value analysis and test result, and make the comparison as the cushion design basis in the process of composite foundation design. Meanwhile, the paper study the methods of composite foundation optimized design and deformation-based control theory design, and points that the finance of the project can be better controlled by the way of deformation-based control theory design, and can achieve the aim of safety and economy. In the paper the method is confirmed through the theoretical analysis and the project practice.