关键词: 干缩开裂, 高密度电阻率, ERT技术, 导电特性, 动态监测

Abstract: In order to investigate soil shrinkage and desiccation cracking process, one-dimensional desiccation cracking tests were
conducted on Xiashu clay and monitored using the electrical resistivity tomography (ERT) technique. During the test, saturated slurry
specimens are prepared and dried under a natural condition. The evolution of electrical resistivity of soil specimen is recorded during
the drying process. Moreover, the desiccation cracking mechanisms are analyzed by comparing desiccation crack patterns and electrical
resistivity images. Experimental results show that the electrical resistivity of soil specimen decreases slightly at the beginning of the
drying process. This is because volumetric shrinkage results in an increase in the contact area between soil particles and the double
layer thickness reduces. Thus, the electrical conductivity of double layer increases. With elapsed drying time, soil specimen becomes
unsaturated and the electrical resistivity transits into the increasing phase. When crack initiates, the electrical resistivity near the crack
increases significantly. Comparing the desiccation crack patterns and electrical resistivity images, it is found that there was a
consistency in terms of crack position and condition. Therefore, the ERT technique is an effective method to dynamic monitor the
development of desiccation cracks and particularly reliable to map their positions. It can be a proper technique for further study on soil
engineering properties under extreme drought climate.

Key words: desiccation cracking, high-density electrical resistivity tomography, ERT technique, electrical conductivity, dynamic
monitoring