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Indexed by:期刊论文

Date of Publication:2019-03-01

Journal:MEASUREMENT SCIENCE AND TECHNOLOGY

Included Journals:SCIE、EI

Volume:30

Issue:3

ISSN No.:0957-0233

Key Words:repeatability; laser speckle; transparent soil; optical measurement; digital image correlation

Abstract:In geotechnical engineering, the measurement of soil deformation is one of the most important foundations of soil mechanics research. Transparent soil is a desired choice to obtain information on spatial deformation inside the soil. Based on this, a novel measuring device was developed to automatically record laser speckle images at different laser cross-sections, and the displacement deformation of transparent soil at arbitrary cross-section positions was determined by the planar digital image correlation (DIC) technique. The measuring system was built with two high-precision motorized linear stages. An industrial camera was used in the system to capture the laser speckle images, and synchronization control methods of both the laser transmitter and industrial camera were introduced. The planar DIC technique employed in this paper has been described in detail. The high-precision motorized linear stages proved to have excellent repeatability and the displacement field of a certain laser cross-section in transparent soil can be obtained. Theoretically, the spatial deformation inside the transparent soil can be built based on the displacement fields of multiple laser cross-sections. Finally, the design scheme was confinned by the model pile experiment. The experiment results show that the automatic measuring system has stable operation, and the deformation of arbitrary laser cross-sections inside transparent soil can be obtained easily. This automatic measurement method can be regarded as an innovation in geotechnical physical model experiments.