MODEL TEST ON UPLIFT CAPACITY OF PILE ANCHORS IN COHESSIONLESS SOIL

Abstract

Experimental investigations on model single pile anchor and pile group anchors of solid wooden pile having diameter of 40mm diameter and 600mm length have been carried out in a model tank of size (850mm x700mm x750mm) and subjected to uplift loads were conducted on uniformly graded 'kharkai' river sand(G=2.63) obtained from Jamshedpur,india. Anchor plate was provided as different widths (B = 80mm and 120 mm) and thickness 12 mm. The pile caps used for single and pile groups. The pile anchors were kept at 3/4 th of total length of pile in different medium of sand. The embedment length to shaft width ratios, L/d=11, L/d=08 and L/d=06, and enlarged base width to shaft width ratios, B/d=2, 3 and center to center spacing of pile anchors in the groups were kept a s 3d. All types of piles and pile groups were tested under vertical uplift loading. The load displacement response, ultimate resistance and variation of group efficiency with L/d, B/d and spacing have been studied quantitatively. Theanalytical model of limit equilibrium method has been proposed to predict the net uplift capacity of pile group anchors. The predicted analytical results were compared with experimental results and other previous researchers work. It was found reasonably good agreement with the experimental and other results.