Abstract

Piled raft foundation (PRF) is a cost effective and sustainable foundation option which can reduce the total and differential settlement, and improve the bearing capacity of the foundation in case of high-rise superstructures or marine structures. This study mainly focuses on a parametric analysis of PRF and also checks the impact of various design parameters on the structural and geotechnical aspects of PRF including the settlement of PRF and its components, raft-soil contact behaviour, bending moment, axial stress on pile, soil stress and settlement in different directions etc. To understand the contribution of piles in PRF, two factors such as relative improvement in the stiffness and settlement ratio are also evaluated. The results of the present study indicate that the differential and reference settlement can be controlled by the addition of piles under the raft, whereas the value of normalized differential settlement remains increasing with an increase in the pile spacing to diameter (s/d) ratio. In case of raft-soil contact behaviour, the contact pressure increases if the raft width is increased, but the rate of increment is prominent in case of a higher number of piles. The raft is showing both the sagging and hogging bending moment and as s/d ratio increases, bending moment also tends to increase.

摘要

桩筏基础（PRF）是一种具有成本效益且可持续的基础选择，可以减少总沉降和差异沉降，并在高层上部结构或海洋结构的情况下提高基础的承载能力。本研究主要侧重于 PRF 的参数分析，并检查各种设计参数对 PRF 的结构和岩土工程方面的影响，包括 PRF 及其组件的沉降、筏土接触行为、弯矩、桩上的轴向应力、不同方向的土应力和沉降等。为了了解桩在PRF中的贡献，还评估了刚度和沉降率的相对改善等两个因素。s/d ) 比率。在筏土接触行为的情况下，如果筏板宽度增加，则接触压力会增加，但在桩数较多的情况下，增量率会显着增加。筏板同时显示下垂和中拱弯矩，并且随着s/d比的增加，弯矩也趋于增加。