Model tests on soil displacement effects for differently shaped piles

Abstract

Transparent synthetic soil synthetic soil surrogates which permit real-time visualisation of soil continuum during testing is a novel development for geotechnical physical model tests. This paper presents model tests on pile penetration effects of differently shaped model piles subjected to axial loads in transparent synthetic soil model. Model piles, made of mortar of square, hexagonal, octagonal and circular shapes were utilised for the research. The transparent soil was made from fumed silica powder and pore fluid containing Paraffin and Technical White Oil. Soil displacement patterns were captured non-intrusively using close range photo grammetry while Particle Image Velocimetry (PIV) was employed to analyse the images. The analysed results revealed that the displacements of soil beneath the square pile aligned perfectly vertical with the edge of the pile, while it inclined with the vertical for piles of other shapes; this angle of inclination θ also varies for the variously shaped piles. This result, which depicts varying displacement patterns of soils beneath the differently shaped piles and marks distinguishable features for each shape of pile is significant. It could be used as the basis for the evolution of design charts and protocols based on shape of piles.