Structural analysis of piled raft foundation in soft soil: An experimental simulation and parametric study with numerical method

Abstract

The high infrastructural demand and the unavailability of proper foundation soil have increased the evolution of combined piled raft foundation (CPRF) in the current generation. The use of CPRF in soft soils has increased immensely in the last few decades. But there is a lack of laboratory experiments to understand the behaviour of CPRF in soft/clayey soil, and hence, this study considers an innovative approach to understand different behaviour of CPRF using clayey soil through laboratory experiments. Two different types of small-scaled CPRF models are prepared with 2 × 2 and 3 × 3 pile groups, and the spacing among the piles as well as the thickness of clayey soil are also altered. Several aspects are studied through the experiments such as load-settlement behaviour, load improvement ratio, behaviour of piles in CPRF, load sharing behaviour, axial forces, raft-soil contact behaviour, bending moment in the raft, etc. Based on the experimental test results, a numerical model is also prepared, and then a parametric study is performed numerically considering a 10-storey residential building. The effect of different pile lengths in CPRF is also checked and the parametric study is conducted with several types of pile arrangements.