الفهرس | Only 14 pages are availabe for public view |
Abstract The analysis of piled raft foundations has improved over the last few decades to account for the combined contribution of raft and piles to provide a more efficient system. In traditional pile-raft systems, piles are connected to the raft and extend down into more competent soil. While these piles are effective in increasing the bearing capacity and reducing the structure settlements, they often lead to significant straining actions at the pile head-raft connection which may constitute the weakest link. An attempt to overcome this weak link (pile head-raft connection) is to disconnect the piles from the raft and to consider these piles as reinforcement to the subsoil (enhancing its bearing capacity) and at the same time acting as settlement reducers. Moreover, the gap between the raft and piles is filled with a cushion of structural fill material. In this unconnected piled raft system, the cushion acts to redistribute the loads between raft and piles. There are few previous studies related to unconnected piled raft foundation system that does not clearly explain the load transfer mechanism and settlement behavior under static and seismic loading conditions. In addition, the use of unconnected piled rafts is not common in construction, and foundation design codes do not specifically address its implementation. In this study, ABAQUS fmite element analysis software is used to investigate the load sharing capacity and mechanism of the unconnected system. The main aim of this thesis is to provide an in depth analysis of the raft-soil-pile interactions in multi-layer under static and seismic load. The effects of cushion, piles number, diameter, and length, spacing, raft thickness and all other parameters are also studied. |