Lateral Response of a Piled Raft under Combined Vertical and Lateral Loading in Cohesionless Medium in 1<i>g</i> Conditions

Abstract

Piled raft foundations are subjected to simultaneous vertical and lateral loads in onshore, nearshore, and marine environment conditions. A limited understanding of the performance of piled rafts in these combined loading conditions motives detailed experimental investigations on piled raft foundations subjected to simultaneous vertical and lateral loads. In this study, the performance of an instrumented piled raft subjected to combined loading in a cohesionless medium under 1g conditions, considering different parameters, such as slenderness ratio, pile spacing, and area ratio, was investigated in detail. The vertical load was applied to the foundation as a fraction of the ultimate capacity of the piled raft (Vmax). The study affirms that the lateral load carrying capacity of a piled raft increases within the range of 30%–70% and 50%–210% with increasing vertical loads to 0.1Vmax and 0.2Vmax, respectively, for different parameters considered in the present study. The moment distribution profile in piles subjected to combined loading is discussed in this paper. The maximum bending moment in piles has been observed to be around 0.25 times the pile length from the pile head. The front pile experiences 14%–28% and 19%–36% greater bending moment than the back pile at vertical loads of 0.1Vmax and 0.2Vmax, respectively. Failure envelopes in the vertical–lateral (V–L) plane were constructed to understand the influence of load combinations on the failure performance of the foundation system.