116 / 2021-12-02 11:59:25

Evolution law of crack space development of expansive soil with low permeability boundary under evaporation condition

Crack propagation; Moisture content; Image processing; Special soil; Permeability

（1）资源开发与利用 > 9. 矿山安全地球物理

The evolution law and the development mechanism are investigated in this paper, which expansive soil crack space under the low permeability boundary soil. With the large-size compacted expansive soil samples, the experimental test of crack development was carried out and the moisture content evolution in the evaporation process was monitored by sensors. The acoustic sounder was selected to measure the change of crack development depth and a self-compiled binary image procedure was applied to extract the unearthed crack area ratio. A crack space model was established based on the horizontal strain incremental constitutive theory. This study conclusively showed that, the moisture content in topsoil decreases faster than that in subsoil under the condition of low permeability boundary. A dynamic triangular balance among moisture content, crack rate, and crack depth has been detected in this study. The change of moisture content could be determined as a paramount factor of crack development. The calculated value of fissure space volume is basic anastomotic with the measured value of slope crack grouting model volume.