Cracking behavior of sisal fiber-reinforced clayey soil under wetting-drying cycles

Abstract

Climate variables such as rainfall and high temperature can influence clayey soil moisture and the development of cracks, which can further give rise to environmental and geological disasters. This study investigates the influence of different soil thicknesses, fiber content, and three wetting-drying cycles on soil moisture evaporation and the formation and development of cracks. A photographing system and weighing equipment are used to track the changes in soil mass and cracks during three wetting-drying cycles. Resulting photos of the cracks are quantified and analyzed by image processing technology. Results show that the thicker soil layer can prolong the normal evaporation phase and reduce the stress concentration on the surface, resulting in a delay in cracking. However, this could lead to the development of wide cracks and the formation of shallow ditches, which is an irreversible process with multiple wetting-drying cycles. Sisal fibers are able to effectively solve the aforementioned problems in terms of, reducing the development of longitudinal and lateral cracks and shallow ditches. This further reduces the rate of sudden cracking and helps to maintain the soil’s structural integrity. The healing ability of wetting-drying cycles for cracks increases with the sisal fiber content. These findings indicate that soil cracking is influenced by many factors, though there are no absolute factors that promote or hinder the development of cracks. Therefore, methods that can amplify the positive effects while weakening the negative effects should be explored.