Seismic Response of Pile-Raft Foundations of a Building on Layered Soil-Based Design in South India

Abstract

This study aims to assess the seismic effects of a mid-rise building on the layered soil medium and to estimate the dynamic impacts of pile raft performance that have been studied using PLAXIS 3D-based finite element analysis, optimization of BSDPT, and economical building design. Further, to understand the stiffness of the raft and the effect of the piles on the surface and inside an excavation. The geotechnical analysis of raft with piles PLAXIS 3D simulation, Poulos-Davis-Randolph (PDR), and Stress Distribution on Pile Top (BSDPT) optimization method indicate the displacements have been reduced by 60% based on superstructure design. The column reactions were estimated by Indian standard code using STAAD-Pro. The study reveals that when the building is as-built on the ground, piled-raft foundations have a considerable favourable influence on the seismic behaviours of the building structure, such as a 20% reduction in load and 2.36 cubic meters (m³) pile volume reduction. This study provides insight into the impacts of pile-raft foundations on the seismic response of pile-raft foundations of the superstructures, helping to fill a knowledge gap and better understanding the dynamic assessment of the layered soil settings.