Abstract
Soil cracks are an important physical property of expanded clay soils accompanied by distinctive morphological features such as Galgi and Silkensides as a result of the expansion and contraction processes by moistening and drying the soil which effect on water movement and its flow into the soil body, Three experiments were conducted to study the pattern of soil cracks formation and to show the extent of the effect of adding sand and sheep residues on the cracks forms. Some morphological characteristics resulted from the cracking process such as Number of separate pieces, Cracks length, Cracks width, Thickness of hard part, Area of cracked pieces and Crack pattern were calculated in this study. The morphological description of the cracks showed a clear difference in their forms and the width of the cracks in proportion to the depth of the cracks with their width. The results showed a decrease in the width and length of the cracks with an increase in the addition of sand and sheep residues. Significant differences appeared in values of Crack Intensity Factor (CIF) when adding sheep residues by 6% compared with 6% sand and control treatment. The value of CIF was (2.25%, 2.60% and 3.78%) for sheep residues, sand and control respectively, thus it affected the behavior and pattern of soil cracks.
