Abstract:
ABSTRACT
The use of single pile, group of piles with pile cap, piled raft foundation system, etc., are prevalent in transferring the super structure load from the soft surface layered soils to the firm underground layers in order to reduce the settlement and improve the bearing capacity. Recent development of disconnected piled raft foundation has gained greater importance in improving the load transfer mechanism among pile, raft and subsoil by reducing the vulnerability of greatest axial force on the pile head which leads to pile failure. The present study aims at analyzing the performance of unreinforced and geogrid reinforced disconnected piled raft foundation under vertical loading using the commercially available finite element software PLAXIS-3D. A parametric numerical study was conducted on unreinforced and reinforced disconnected piled raft foundation to explore the effect of varying pile stiffness as well as the inclusion of geogrid layer on the load vs settlement, the load sharing ratio of piles and raft, and the distribution of axial load and bending moment along the length of the pile. The Mohr-Coulomb model was used for the granular cushion layer while the Modified Cam Clay model was used for soft clay underlain the sand layer. Raft and piles were assumed to be rigid and linear elastic. The results showed that axial force taken by piles with higher stiffness was maximum while settlement at the bottom tip of the pile with higher stiffness was maximum in both reinforced as well as unreinforced disconnected piled raft system.
Key words: Disconnected Piled Raft, PLAXIS 3D, Geogrid, Axial Load, Bending Moment.
Abstract: Theme 1