Spatial deformation measurement using transparent soil

Magued Iskander, Jinyuan Liu

Research output: Contribution to journalArticle

Abstract

This paper addresses the need for nonintrusively measuring spatial deformation pattern inside soils. In this study, transparent soil surrogates are used in model tests instead of natural soils. Transparent soil with macrogeotechnical properties similar to those of natural soils was made of either transparent amorphous silica gels or powders and a pore fluid with a matching refractive index. An optical system consisting of a laser light, a line-generator lens, a charge-coupled device (CCD) camera, a frame grabber, and a computer was developed to optically slice a transparent soil model. A distinctive speckle pattern is generated by the interaction of the laser light and transparent soil. The laser speckle images before and after deformation were used to nonintrusively measure the relative displacement field using digital image cross-correlation. Spatial displacement fields under a model footing were obtained by combining several cross-sections in MATLAB®. Test results showed that the developed optical system and transparent soil are suitable for studying soil-structural interaction problems.

Original languageEnglish (US)
JournalGeotechnical Testing Journal
Volume33
Issue number4
DOIs
StatePublished - Jul 2010

Fingerprint

Soils
soil
laser
speckle
Speckle
Optical systems
Lasers
footing
Silica gel
refractive index
CCD cameras
digital image
model test
MATLAB
Lenses
Refractive index
gel
silica
cross section
Powders

Keywords

  • Digital image cross-correlation
  • Displacement field
  • Image processing
  • Model tests
  • Non-intrusive measurement
  • Optical test
  • Particle image velocimetry
  • PIV
  • Three-dimensional analysis
  • Transparent soil

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology

Cite this

Spatial deformation measurement using transparent soil. / Iskander, Magued; Liu, Jinyuan.

In: Geotechnical Testing Journal, Vol. 33, No. 4, 07.2010.

Research output: Contribution to journalArticle

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