Analysis of Pile Group and Piled Raft as a Foundation System

Abstract

Nowadays in most high-rise buildings, the combination of both piles and raft are used since only raft cannot satisfy design requirements. So, by addition of piles with raft load carrying capacity also increase sand also reduces settlement. Piled Raft foundations have been considered as one of the most economical foundation systems and are widely used to support high-rise structures. In the present study, 3D finite-difference analysis was performed on Piled Raft foundation using FLAC3D software. In this mostly sandy soil is taken in two different layers (different Young’s modulus). Here, the analysis is done on both Pile Group and Piled Raft. In Pile Group, the pile cap is not in contact with the ground surface. In Piled Raft, raft top surface level is in the same level with the ground surface level. Also, load had been applied in two ways concentrated load at the center of the pile cap/raft and uniformly distributed load over the pile cap/raft. The effect of varying Pile cap/raft thickness has been considered in the paper. The diameter of pile is taken as 800 mm. The pile length taken is 35 m. The different load is applied to the different group of piles according to their safe bearing capacity. The result shows that as pile cap/raft thickness increases then the differential settlement decreases. By increasing pile cap/raft thickness, the maximum bending moment and maximum shear force increases. Result is also affected by different methods of loading. Differential settlement is less in case of uniformly distributed load compared to concentrated load at the center.