Experimental Studies on Settlement Search of Piled Raft System

Present study is an experimental work to analyse the effect of size of raft, length, number of piles on the settlement of the foundation system. In this work, study has been carried out to understand the load sharing ratio of the pile and raft with different patterns of pile and of different lengths. It was observed that, the load carrying capacity increases and settlement ratio reduces for the piled raft foundation tested on dry sandy soils deposits with relative density 70%. Total 39 tests were carriedout for the different piled raft models of different raft sizes (15 x 15 cm, 17.5 x 17.5 cm, 20 x 20 cm), number of piles (4 nos., 5 nos., 9 nos.) and of different pile lengths (10 cm, 20 cm, 30 cm, 40 cm). With the increase in raft size, load carrying capacity increased from 8.9 kN (for 15 cm raft) to 10.54 kN (for 17.5 cm raft), 17.22 kN (for 20 cm raft) for 25 mm settlement. Length of pile considerably effect on the foundation settlement, for 5 kN applied load, raft settlement (15 x 15 cm) without pile was 10 mm which reduces to 3 mm, 2.4 mm, 1.8 mm and 1.4 mm for 10 cm, 20 cm, 30 cm and 40 cm pile lengths respectively. Similar results were observed for other pile dimensions. Additionally, it is also observed that, pile number has considerable effect on the load carrying capacity and settlement of foundation system.