Plugging of Closed and Open-ended Pipe Piles in Sands

Plugging of pipe piles is an important phenomenon, which is not adequately accounted for in the current design recommendations of open ended pipe piles. An open-ended pipe pile is said to be plugged when the soil inside the pile moves down with the pile, resulting in the pile becoming effectively closed-ended. Plugging is believed to result in an increase in horizontal stresses between the pile and the surrounding soil, which results in an increase in skin friction. The present study investigates the effect of plug on pile load capacity and effect of plug removal. Different parameters are considered such as pile diameter to length ratio, type of installation in sand of different densities, removal of plug in three stages (50%, 75% and 100%) with respect to length of plug. Kerbala sand, which is used as a foundation soil is poorly graded clean sand. The sand was prepared at different densities using a raining technique. To simulate the pile load test in the field, a new apparatus was manufactured. A driving-pressing system for pile installation was manufactured in this study. The soil plug is removed by a device manufactured to remove the soil column entrapped inside the pipe piles