Experimental investigation of skin friction response of RC piles in hard limestone rocks

摘要

The pile foundations are widely applied in Riyadh, Kingdom of Saudi Arabia, during the last two decades for many projects such as Riyadh metro, multi-story buildings, bridges, tunnels, and other structures. The pile foundation system is used in Riyadh city not because of the weakness of the limestone rock layers but because of space and time limitations, economic issues, and difficulty of transferring the utilities. The pile foundation transfers the superstructure load to the rock layers by means of skin friction and end bearing resistance. In this paper, four pile load experiments were performed to describe practically the process of transferring the load via skin friction on reinforced concrete piles with different lengths and diameters constructed on large samples of limestone rock. A soft material (Styrofoam) was put underneath the pile to remove the effect of resistance due to end bearing. The test results of the ultimate skin friction were predicted using some of the methods available in the literature. For some of the available methods, a close proximity was observed between the test results and the predicted values.