Factors Influencing the Accuracy of the Photogrammetry-Based Deformation Measurement Method

Abstract

Triaxial test has been widely used to investigate the stress—strain relationship of unsaturated soils. During triaxial testing, soil volume is an essential parameter to be measured. For an unsaturated soil, due to the presence of air phase, accurate volume/deformation measurement during triaxial testing was a great challenge for researchers. Recently, a photogrammetry-based method has been developed to measure the soil volume/deformation during triaxial testing. Preliminary triaxial test results indicate the new method is simple, accurate, and cost- and time-effective. However, some concerns regarding its measurement accuracy and applicability, which are critical for the dissemination of the photogrammetry-based method, have been raised by other researchers. These concerns were addressed in details in this study. The factors concerning the deformation measurement accuracy were systematically evaluated through a series of triaxial tests on an aluminum cylinder with different confining media and chamber pressures. A sensitivity analysis was carried out to investigate the impact of the system parameters on the volume measurement accuracy of the photogrammetry-based method. In addition, a triaxial test on a saturated sand specimen was conducted to evaluate the influences of mesh density, mesh pattern, and interpolation technique on the volume change measurement accuracy. Finally, some suggestions were provided to improve the accuracy of the photogrammetry-based measurement method.

Department(s)

Civil, Architectural and Environmental Engineering

Keywords and Phrases

Optical ray tracing; Photogrammetry-based method; Triangular mesh; Triaxial test; Unsaturated soil; Volume change

International Standard Serial Number (ISSN)

1861-1125; 1861-1133

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2019 Springer Verlag, All rights reserved.

Publication Date

01 Apr 2019

Link to Full Text

Share

 
COinS