Geo-Congress 2020
A Least Square Optimization Approach for Determining the Soil Boundary and Absolute Volume of Unsaturated Soils
Publication: Geo-Congress 2020: Geo-Systems, Sustainability, Geoenvironmental Engineering, and Unsaturated Soil Mechanics (GSP 319)
ABSTRACT
Triaxial tests have been widely used for evaluating the stress-strain behavior of both saturated and unsaturated soils, in which, the volume measurement is a very important component; however, existing methods can only measure relative volume changes during triaxial testing. Recently a photogrammetry-based method has been proposed to measure volume changes of both saturated and unsaturated soil. Although this method has many advantages over conventional methods, it still has one drawback: the incapability to determine the top and bottom boundaries of the soil sample in the triaxial testing. In order to overcome this limitation, a least-square optimization approach and 3D reconstruction of triaxial testing were performed using the photogrammetry-based method. Many validation tests have been performed to calculate the distance between the top and bottom boundaries that confirmed the accuracy of the proposed method. This proposed method demonstrated very high accuracy by comparing the results and the measured distance with a difference of 0.0807 mm.
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REFERENCES
Morgenstern, N. R., and Fredlund, D. G. (1976). “Constitutive relations for volume change in unsaturated soils.” Canadian Geotechnical Journal, 13(3), 261–276.
Bishop, A. W., and Blight, G. E. (1963). “Some aspects of effective stress in saturated and partly saturated soils.” Geotechnique, 13(3), 177-197.
Fredlund, D.G.; Rahardjo, H. (2009). “Soil mechanics for unsaturated soils.” Soil Dynamics and Earthquake Engineering, Elsevier BV, 12(7), 449–450.
Bishop, A. W. “The Measurement of Pore Pressure in Triaxial Test,” in Proc. Conf Pore Pressure and Suction in Soils. London: Butterworths, 1960, pp. 38-46.
Yin, J. H. (2003). “A Double Cell Triaxial System for continuous measurement of volume changes of an unsaturated or saturated soil specimen in triaxial testing.” Geotechnical Testing Journal, 26(3), 353–358.
Zeng, F., and Shao, L. (2016). “Unloading elastic behavior of sand in cyclic triaxial tests.” Geotechnical Testing Journal, 39(3), 462–475.
Wong, J. M., Elwood, D., and Fredlund, D. G. (2018). “Use of a three-dimensional scanner for shrinkage curve tests.” Canadian Geotechnical Journal, Canadian Science Publishing, 56(4), 526–535.
Zhang, X., Li, L., Chen, G., and Lytton, R. (2014). “A photogrammetry-based method to measure total and local volume changes of unsaturated soils during triaxial testing.” Acta Geotechnica, Springer Verlag, 10(1), 55–82.
Li, L., Zhang, X., Chen, G., and Lytton, R. (2015). “Measuring unsaturated soil deformations during triaxial testing using a photogrammetry-based method.” Canadian Geotechnical Journal, Canadian Science Publishing, 53(3), 472–489.
Li, L., and Zhang, X. (2019). “Factors influencing the accuracy of the photogrammetry-based deformation measurement method.” Acta Geotechnica, Springer Verlag, 14(2), 559–574.
Salazar, S. E., Miramontes, L. D., Barnes, A., Bernhardt-Barry, M. L., and Coffman, R. A. (2019). “Verification of an internal close-range photogrammetry approach for volume determination during triaxial testing.” Geotechnical Testing Journal, ASTM International, 42(6).
Information & Authors
Information
Published In
Geo-Congress 2020: Geo-Systems, Sustainability, Geoenvironmental Engineering, and Unsaturated Soil Mechanics (GSP 319)
Pages: 394 - 401
Editors: James P. Hambleton, Ph.D., Northwestern University, Roman Makhnenko, Ph.D., University of Illinois at Urbana-Champaign, and Aaron S. Budge, Ph.D., Minnesota State University, Mankato
ISBN (Online): 978-0-7844-8282-7
Copyright
© 2020 American Society of Civil Engineers.
History
Published online: Feb 21, 2020
ASCE Technical Topics:
- Analysis (by type)
- Domain boundary
- Engineering fundamentals
- Geomechanics
- Geotechnical engineering
- Laboratory tests
- Least squares method
- Mathematics
- Models (by type)
- Optimization models
- Regression analysis
- Saturated soils
- Soft soils
- Soil mechanics
- Soil properties
- Soil stress
- Soils (by type)
- Statistical analysis (by type)
- Tests (by type)
- Triaxial tests
- Unsaturated soils
Authors
Metrics & Citations
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