Load sharing raft and piles in piled raft foundation

Abstract

Current pile foundation design for large-load structures often assumes piles alone bear the entire load, neglecting the contribution of the mat foundation in contact with the soil, leading to inefficiencies in load-bearing calculations. Due to the complexity of piled raft foundations and a lack of efficient design solutions, this study develops a numerical model to analyze load-sharing between raft and piles, incorporating theoretical analysis, small-scale model experiments, and finite element methods to address complex interactions such as pile-to-pile, pile-to-raft, raft-to-soil and pile-to-soil. By examining load distribution based on factors like pile quantity, spacing, and raft size, with cases including a single pile, the pile groups consisted of 2x2 piles and 3x3 piles, the study establishes a design model to predict settlement and load distribution between raft and piles. The results indicate that an efficient design approach for piled raft foundations can focus on two primary criteria: settlement and load-sharing, making this method suitable for preliminary foundation design.

Keywords: Piled raft; load-sharing; small-scale model; settlement.