New approach to group pile load estimation

Abstract

Current literature lacks an analytical method for estimating pile load distribution due to the statically indeterminate nature of pile groups. In practice, such estimations are accomplished by finite-element-based analyses or numerical interaction methods, which require computer implementations. A disadvantage of these implementations is that they extend the total duration time and cost of a project. In order to address this issue, a group pile load formula was developed based on 120 finite-element (FE) model configurations. The group pile load formula incorporates the dimensions of a rectangular raft, diameter, length and spacing of piles, vertical uniform pressure, soil moduli up to five layers, ultimate pile-soil and pile-tip resistance, and the elastic modulus of piles. The formula is capable of calculating pile loads at 25 different locations. Additionally, the portion of load carried by the piles as well as through the raft-soil contact can be estimated. Predictions from the FE model and the formula were verified with respect to the observed results from three case studies. The formula developed will help engineers to optimize their group pile configurations efficiently by providing an accurate group pile load estimation.