Finite Element Analysis Of Rigid-flexible Pile Composite Foundation Based On The ABAQUS Software

Rigid-flexible pile composite foundation is a special form of long and short pile composite foundation, which belongs to the category of foundation treatment. The pile body is composed of long rigid pile and short flexible pile,and combines with soil between piles to form a foundation to bear the load of superstructure. In recent years, this new type of foundation treatment is more and more widely used, especially in deep soft soil. Compared with the traditional foundation form, it has a significant advantage in the control settlement deformation.Based on ABAQUS finite element analysis software, the pile-soil model of rigid-flexible pile composite foundation was built to have a numerical analysis.Based on the settlement control design theory, a model of 5×5rigid-flexible-piles composite foundation was established to make a scheme optimization. Then, according to the optimum scheme and under the horizontal load, stress characteristics were analyzed for further optimization. The specific content includes the following aspects:(1)Based on the background of the development of composite foundation, the composition of rigid-flexible pile composite foundation, working mechanism and failure modes were discussed. The paper also discussed the similarities and differences of natural soil, pile foundation and composite foundation, and compare with rigid long and short pile composite foundation to explain the use range and use conditions of rigid-flexible pile composite foundation.(2)The paper analyzed the settlement design and bearing capacity design of the rigid-flexible pile composite foundation, and summed up the principles andsteps of design theory of settlement control. The paper also analyzed the calculation method of horizontal bearing force for single pile and pile group.(3)The paper introduced the finite element analysis software of ABAQUS, and summarized the problems when using it. A detailed description of the process of rigid-flexible pile composite foundation model was also established.(4)Through simulating the different pile arrangement plans under vertical uniform load, the rule of settlement under cap was discussed on the condition of invariable total number but the proportion of the rigid pile changes.(5)The rationality of design theory of settlement control was proved when it was used in deep soft soil. Then, according to the optimum scheme, the paper focused on the stress characteristics when the modulus of cushion, rigid pile and flexible pile changes.(6)Combining with the rules of settlement property and stress characteristics, the paper puts forward some valuable suggestions to the engineering practice according to the optimal scheme.