Abstract:

In this paper , first , the soil under a piled raft foundation was simulated via the linear extended DruckerPrager elastic-plastic model. Next , behaviors of the piled raft foundation system were revealed by using a 3D finite element model based on the ABAQUS program. Then , the dimensional eight-node solid element , the four-node thick plate element and the 3 D finite element coupling interface element were adopted to respectively simulate piles and the soil in the model , the piled raft and the raft-soil system , thus obtaining the operation characteristics of the piled raft foundation. Moreover , the design method of composite pile foundation was investigated and an improved method based on a "three-stage" concept was presented according to the criterion of "Code for Design of Building Foundation". The two methods were finally applied to a practical engineering. Results show that , as compared with the conventional design method , the two above-mentioned methods are more feasible , practical and economical.

Key words: foundation, pile, finite element analysis, seulement, elastic-plastic foundation model, "three-stage", design