Quantification and characterization of temperature effect on desiccation crack network in soil

Laboratory tests were conducted on soil to investigate the desiccation cracking behavior at different temperatures (22, 60 and 105 C). The initiation and propagation of desiccation cracks during drying was monitored using a digital camera. By applying image processing technique, the geometrical parameters of the crack networks were quantitatively determined. The distribution characteristics of crack width, length and clod area were described by employing statistical method. In addition, the surface crack ratio Rsc (the surface of cracks to the total surface) was introduced to quantify surface cracking extent at different water contents. The results show that soil desiccation cracking behavior and the geometrical characteristics of crack networks depend strongly on temperature. On the whole as the temperature increases, crack initiates earlier and the extent of cracking also increases. The final surface crack ratio, number of clods per unit area, average length of cracks and average width of cracks increases with increasing temperature, while the average area of clods, number of nodes per unit area and number of crack segments per unit area decreases with increasing temperature. The statistic results of the crack parameters indicate that the increase of temperature increase the probability of initiating longer and wider cracks and smaller clods during drying.