TY - GEN
T1 - Speckle photography for measuring 3-D deformation inside a transparent soil model
AU - Liu, J.
AU - Iskander, M.
PY - 2009
Y1 - 2009
N2 - This paper addresses the needs for non-intrusively measuring 3-D internal soil deformation for various geotechnical engineering problems. In this study transparent soils are used to model a soil profile of sand overlying soft clay. Transparent soils are made of either transparent amorphous silica gels or powders with a pore fluid having the same refractive index. Conventional geotechnical tests showed that transparent soil exhibited macro-geotechnical properties similar to those of natural soils. A comparison study also showed that transparent soils can be used to simulate natural soil in model tests. An optical system consisting of a laser light, a CCD camera, a frame grabber, and a computer was developed to optically slice the transparent soil model. A distinctive laser speckle pattern is generated by the interaction between laser light and transparent soil. Speckle photography was used to calculate the 2-D displacement field by cross-correlating two consecutive images captured during footing settlement. A 3-D displacement field under a model footing was obtained in Matlab® by combining multiple slices of 2-D displacement fields. Test results showed that the developed optical system and transparent soil are suitable for studying 3-D soil-structural interaction problems
AB - This paper addresses the needs for non-intrusively measuring 3-D internal soil deformation for various geotechnical engineering problems. In this study transparent soils are used to model a soil profile of sand overlying soft clay. Transparent soils are made of either transparent amorphous silica gels or powders with a pore fluid having the same refractive index. Conventional geotechnical tests showed that transparent soil exhibited macro-geotechnical properties similar to those of natural soils. A comparison study also showed that transparent soils can be used to simulate natural soil in model tests. An optical system consisting of a laser light, a CCD camera, a frame grabber, and a computer was developed to optically slice the transparent soil model. A distinctive laser speckle pattern is generated by the interaction between laser light and transparent soil. Speckle photography was used to calculate the 2-D displacement field by cross-correlating two consecutive images captured during footing settlement. A 3-D displacement field under a model footing was obtained in Matlab® by combining multiple slices of 2-D displacement fields. Test results showed that the developed optical system and transparent soil are suitable for studying 3-D soil-structural interaction problems
KW - Digital image cross-correlation
KW - Internal 3-D displacement field
KW - Optical test
KW - Speckle photography
KW - Transparent soil
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U2 - 10.3233/978-1-60750-031-5-498
DO - 10.3233/978-1-60750-031-5-498
M3 - Conference contribution
AN - SCOPUS:84865166282
SN - 9781607500315
T3 - Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering: The Academia and Practice of Geotechnical Engineering
SP - 498
EP - 501
BT - Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering
T2 - 17th International Conference on Soil Mechanics and Geotechnical Engineering, ICSMGE 2009
Y2 - 5 October 2009 through 9 October 2009
ER -