Cement Pile Bearing Behavior Of The Three-dimensional Elastic-plastic Composite Foundation

With the rapid development of national economy and the constant enlargement of the basic civil engineering, soft grounds have been found in all kinds of civil engineering, and they would be treated so as to meet the demands of the buildings. Many effective methods of ground treatment have been explored in long project practice. The cement-mixing pile(CMP) composite foundation is one of methods having widely been used in engineering because of its unique merits. To promote the application and development of CMP composite foundation, the multi-pile composite foundation for elasticity and plasticity has been analyzed in this paper by application of 3-dimension non-linear finite element.The mechanism of the carrying capacity of CMP composite foundation as well as the finite element method and the displacement mode of the element and soil's mode has been introduced. The basic design and calculation methods have been summarized in the paper. Afterwards the influence factors in CMP composite foundation have been analyzed. They are the several aspects as the followings:1 , The influence of the pile modulus on the deformation of CMP composite foundation and on the stress of pile and soil were analyzed;2, The influence of the replacement ratio on the deformation of CMP composite foundation was analyzed;3, The influence on the length of pile on the deformation of CMP composite foundation was introduced;4, The adjustment function of cushion from its thickness and modulus on the stress of pile and soil was studied.The field static load test result and the calculation result obtained from finite element program are compared. It indicates that the curves obtained from finite element program can match the field static load test. The finite element method introduced in the paper can be applied for the analysis of CMP composite foundation and the result of program can be used as reference of project design.