Numerical Study on the Influence of Load Type on the Behavior of Piled Raft Foundation in Clay Soil

Abstract

The effect of the load type on the behavior of a large piled raft foundation (PRF) with an intermediate flexible raft in stiff clay soil has been investigated. For this purpose, three-dimensional numerical analyses have been carried out for the piled raft with varying pile configurations subjected to either uniformly distributed load (UDL) or equivalent point loads (PL). The average and differential settlements, raft bending moment, and pile axial load distribution are evaluated and discussed in detail. Results show that for piles covering the maximum area of the raft, the average settlement for the PL case is always marginally higher compared to the UDL case, whereas the differential settlement is substantially greater. The raft bending moments for PL are always significantly higher than for UDL. For UDL, the pile axial load distribution is predominantly affected by the pile positions, and for the PL, it is mainly affected by the column point load locations in addition to pile positions. Based on the loading intensity and serviceability limit considerations, the optimum pile configuration has been determined for the PRF under column point loads.