The Effect Of Changing The Shape Of Cross Section On Bearing Capacity Of Precast Concrete Model Piles Driven In Sand In The Laboratory.

Abstract

Piles foundations are one of the important solutions as structures foundations, that motivate researchers to develop their working field in most soils, and among these fields is the issue of driven piles in sand which is the base of this research.

In case of driven piles, carried stresses are distributed into surrounding soils via two separate mechanisms, the first through pile tip to the soil below, and the second is friction developed between pile shaft and surrounding soil, researches continues in pile filed to fully understand those two mechanisms and calculating  and developing pile bearing capacity using deferent methods.

Currently researchers enhancing bearing capacity by changing geometrical properties, as the shaft aria is increased by changing cross section shape, using X shaped cross sections and Y shaped cross sections, where shaft area of these piles are higher than piles with square or circular cross sections with the same area.

The aim of this research is to study the effect of changing cross section shape on ultimate bearing capacity of precast concrete model piles driven in sand, by conducting loading tests on three laboratory model piles, the first with square cross section the second is X shaped and the third is Y shaped cross section, all models have the same cross section area , and the same length driven in sand, but shaft area changes, the X model have the highest shaft area, followed by Y model, then the square model, the test showed similar behavior under  axial loads, but ultimate bearing capacity  defers with cross section, and increase with the increase of shaft area.