Carrying Capacity of Model Steel Pile Foundation with Different Cross-Sectional Shapes in Sand

Abstract

In present time, the steel piles are widely used for foundation of various structures constructed onshore and offshore. They are getting popularity because of easy availability, handling and splicing, and also durable. In the present investigation, the load-carrying capacity was compared of model steel piles having different cross-sectional shapes under vertical load in sand by keeping the equal cross-sectional area and equal length of pile. For this purpose, model steel piles of different shapes, i.e., solid circular, hollow circular, L-shaped, and H-shaped pile having equal cross-sectional area (A = 1.767 cm2) and equal embedded length 30 cm and total length of 33 cm were used. For this work, the effect of shape of single model pile and model pile group of 2 × 2 with spacing 3d, 4d, 5d on load-carrying capacity was studied in sand of two different relative densities under vertical load. For experimental work, circular tank of diameter 90 cm and height 60 cm was used and natural Bahadarpur sand near Sankheda, Vadodara district of Gujarat having angle of internal friction (φ) = 34• and density (ρ) = 1.687 g/cm3 (60% relative density) and angle of internal friction (φ) = 40• and density (ρ) = 1.747 g/cm3 (80% relative density) was used. The load was applied at the center of pile cap through jacking mechanism and pile cap was kept 3 cm above the soil layer to neglect the effect of cap in the capacity of pile. From investigation of results, it has been observed that the load-carrying capacity of H-shaped single pile is more as compared to all other cross-sectional shapes in 60% as well as 80% relative density. In pile group, all shapes of pile show an increase in load-carrying capacity with an increase in spacing from 3d to 4d and 5d but capacity trend is different in H-shaped pile as here the load capacity decreases with increasing spacing in both 60% and 80% relative density. Consequently in pile group the hollow circular pile shows maximum capacity with increasing spacing and relative density.