Fig 1.
Red clay (left) and expansive soil (right).
Table 1.
The basic physical property indexes of red clay.
Table 2.
The basic physical property indexes of expansive soil.
Table 3.
Test grouping.
Fig 2.
Schematic diagram of the test device.
Fig 3.
Flowchart of the operational steps of the XTDIC system.
Fig 4.
Detailed diagram of the operational steps of the XTDIC system.
a. Feature Point Calibration. b. Seed Point Generation. c. Formation of Speckle Field. d. Compute experimental outcomes and generate contour plots.
Fig 5.
Binocular stereo vision schematic.
Fig 6.
Schematic diagram of the orientation of each point.
Fig 7.
Displacement in all directions on the surface of red clay.
a. (X direction). b. (Y direction). c. (Z direction).
Fig 8.
Displacement in each direction on the expansive soil surface.
a. (X direction). b. (Y direction). c. (Z direction).
Fig 9.
Schematic diagram of the stress on the soil sample during the drying process.
Fig 10.
Anisotropic shrinkage of expansive soil and red clay.
a. shrinkage of red clay. b. shrinkage of expansive soil. c. Lateral shrinkage comparison. d. Longitudinal shrinkage comparison. e. Vertical shrinkage comparison.
Fig 11.
Maximum principal strain cloud of red clay.
a.10min. b.240min. c.520min. d.750min.
Fig 12.
Maximum principal strain cloud of expansive soil.
a.10min. b.350min. c.630min. d.960min.
Fig 13.
Internal particle distribution and three-phase diagram of soil at each stage of soil mass.
a. Initial particle distribution, pore size and three-phase diagram of soil. b. Particle distribution, pore size and three-phase diagram of soil after drying for a certain period of time.
Fig 14.
The pore ratio of soil samples varies with moisture content.
a. red clay. b. expansive soil.