Journal Published Online: 23 February 2015
Volume 38, Issue 5

Analysis of Piles Under Oblique Pullout Load Using Transparent-Soil Models



This paper presents an experimental investigation of internal deformation in transparent sand caused by a pile moving under oblique pullout loads using the digital image correlation (DIC) technique. Transparent sand used in this study is manufactured with fused quartz and a pore fluid (mixture of Norpar 12 and white mineral oil) with a matching refractive index. An optical system consisting of a linear laser, a charge-coupled device (CCD) camera, an optical platform, a frame grabber, and a computer is employed. During the test process, the speckle (which is the interaction between the transparent-soil matrix, impurities, entrapped air, and laser) is generated. The laser speckle images before and after soil deformation are used to measure the relative displacement field using the DIC technique. The belled wedge pile, conventional tapered pile, and equal section pile with the same volume, slenderness ratio L/D = 16.9, and oblique pullout loads at angles α = 0°, 45°, 60°, and 90° are conducted in transparent sand. The load-displacement response, oblique ultimate pulling resistances, internal deformation field, surface heaving, and failure mechanisms have been studied. The normalized values in this paper were compared with previously measured values. The results indicate that the optical system and transparent sand are suitable for studying soil deformation caused by pile–soil interaction under oblique pullout loading.

Author Information

Kong, Gang-Qiang
Hohai Univ., Nanjing, Jiangsu, CN
Cao, Zhao-Hu
Hohai Univ., Nanjing, Jiangsu, CN
Zhou, Hang
Hohai Univ., Nanjing, Jiangsu, CN
Sun, Xue-Jin
Hohai Univ., Nanjing, Jiangsu, CN
Pages: 14
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Stock #: GTJ20140109
ISSN: 0149-6115
DOI: 10.1520/GTJ20140109