Bearing capacity of closed and open ended pipe piles installed in loose sand with emphasis on soil plug

Abstract

Present study investigates the behaviour 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 loose sand, removal of plug in three stages (50%, 75% and 100%) with respect to length of plug. Kerbala sand from Iraq, which is used as a foundation soil is poorly graded clean sand. It was concluded that the percentage of reduction in pile load capacity for open–ended pile increases with increase of the length of removal of the soil plug. Open-ended pipe pile behaves as a closed-ended if the soil plug formed inside piles is in state of partial plug or full plug. The failure of a pile to plug during driving does not necessarily mean that it will not plug during static loading, since inertia effects, which are present during driving are absent during static loading. This can be observed from the load-settlement curves where the open-ended piles exhibit large resistance to penetration due to mobilization of internal friction during static loading.