GROUP EFFECT ON VERTICALLY LOADED PILES IN SAND

Abstract

P ile foundations are one of the common means of transferring structural loads to the soil in depth • and have been extensively used in both clays and sands; Pile- groups used as foundations of the structures are subjected to heavy vertical loads due to live load and dead load of the superstructure. The safety of these structures depends on the ability of the supporting piles to Iran smit the resulting forces safely. An experimental investigation was performed on 15 mm outer diameter and 12.5 mm inner diameter alumi- nium model pilee. A 125 cm wide . end. 125 cm long and 75 cm deep wooden tank ',,as i.11Ld with band in which pile groups were jut before filling sand, Needle type concreto vibration was used for compacting the sand. . procedure was developed for the placement of sand , which gave good rep eoducibility ;. Pile groups of 2 2 2 2 group , 3 group and 4 group were tested as capped groups(i.e, pil:;d foundations) with the pile cap in contact with the sand surface, with respect to spacing of piles, in the laboratory. In addition , 2 2 group was tested as free standing pile group, The centre to centre distance between tho piles was kept as 2 d, 3 d, 4d, 5 d, 6 d., and 8 d, where d is the diameter of the pile. Two singlo 'pilos were tested with each group for comparison.