Model Tests on Soil Movement during the Installation of Piles in Transparent Granular Soil

This paper presents model tests on the displacement characteristics of flat-ended piles, pipe piles, and piles with a cone tip of 45 degrees in a transparent granular soil. The testing setup consisted of transparent granular soil, a penetration device, a linear laser, a charge-coupled device (CCD) camera, and an optical platform. The transparent granular soil used in this study were made of fused quartz and a pore fluid with the same reflective index. The pore fluid was a mixture of n-paraffin C-12 and food-grade White Oil 15. The positions of the granular-soil particles were registered by laser speckles, and the internal displacements of the particles during penetration were recorded by the CCD camera. The horizontal and vertical displacements of the granular soil and the zone of influence of penetration of different piles were determined by comparing the images of the granular soils before and after penetrations. On the basis of these data, the displacement field and sheltering effect of different piles are discussed, and the responses of the granular soil to the penetration of different types of piles are evaluated and compared.