Research On Settlement Characters Of Composite Piled Raft Foundation Based On Abaqus

The initial vertical supporting stiffness is evenly distributed in natural foundation and uniform pile composite foundation. When the foundation on the ground is applied an uniform load, the settlement deformation will be large in the middle of the foundation and small in the side of the foundation. The deformation just likes a dish. When superstructure loads are not uniform like frame-tube structures and shear wall frame interaction, the differential settlement will be larger, if we still take the conventional design concepts to design the ground treatment. As we know the differential settlement is harmful to reliability of structure, so how to regulate the differential settlement in a reasonable zone appears very important. Based on the concept of adjusting foundation rigidity design for reducing differential settlement, the author put forward the idea of taking variable stiffness composite piled raft foundation to treat the ground in this paper. Then the author research on settlement characters of variable stiffness composite piled raft foundation by simulation. Damage-reduction Seismic Theory of Multi-ribbed Slab Structure (50878021).In this essay, firstly introduce the concept and theoretical basis of adjusting foundation rigidity design for reducing differential settlement. Then disuss the relevant issues about taking advantage of ABAQUS to simulate composite foundation. The author solved some issues such as how to balance the initial geostress of the ground, how to treat pile-soil contact, how to define material parameters in ABAQUS.In this paper the author builds three-dimensional, non-linear FEA models with ABAQUS to simulate natural ground supporting raft foundation, variable stiffness composite piled raft foundation and just partial pile supporting raft foundation in the middle of the raft. Through comparative analysis, we can know that differential settlement can be effectively reduced by taking variable stiffness composite piled raft foundation to treat the ground, especially in frame-tube structures and shear wall frame interaction. The same as the treatment can reduce the hazard occurred in foundation and superstructure. Then the author analyze the settlement characters of foundation with different thickness of raft, deformation modulus and thickness of cushion, elastic modulus of pile, deformation modulus of soil beside pile and deformation modulus of soil local in pile tip by simulation. The author expects the results can provide reference for the engineering practice.