Bearing Capacity and Settlement Study on Small-Scale Piled-Raft Groups in Sand

Abstract

Pile group foundation with a pile cap can be considered as a piled-raft foundation. Previous studies indicate that in a piled-raft foundation, the piles contributes to reduce settlement of the raft whereas the raft provides an additional bearing capacity of the pile group. Laboratory testings were performed to investigate the performance of piled-raft group from bearing capacity and settlement point of views. Instrumented laboratory models of 2×2 and 3×3 piled-raft group were loaded vertically to obtain load vs. settlement curves and load-transfer to raft, to pile shaft, and to pile tip. From the load-settlement curves of piled-raft group, the performance of bearing capacity and settlement was then observed and quantified. The laboratory test results indicated that the presence of piles reduced the settlement of raft significantly, whereas the presence of raft provided additional bearing capacity to the pile.