Experimental Investigation on Behavior of Piled- Raft Foundation

Abstract

Abstract-In the piled-raft foundation systems the load is assumed to be shared between the piles and raft. Therefore, this improves the ultimate load capacity and reduces settlements in a very economic way as compared with the traditional foundation concepts. The use of strategically located piles improves the load capacity of raft and reduces the differential settlement. This research sheds some light on the philosophy of using piles as settlement reducer for raft foundation and also the behavior of pile length and alignment on the attained ultimate load are experimentally investigated. The experimental program includes the model test on unpiled raft, raft supported by single pile, (2x2), (3x3) and (4x4) pile groups. From the accomplished studies, it has been concluded that as the number of piles underneath the raft increases, load carrying capacity of foundation increases. Also, there is a negligible effect on load improvement ratio and settlement reduction ratio with increase in raft thickness and number of piles. The observed settlement values from Experimental study was compared with numerical modeling using PLAXIS-3D and found the results are in good agreement. Keywords- Piled-Raft, PLAXIS-3D, Ultimate Load, Foundation.