ABSTRACT
Cracks are widely present in slope soils. Cracks can be classified in several ways, namely, structural, desiccation, shearing, and freeze-thaw cracks. It is well recognized that cracks can induce slope instability (Baker, 1981; Lee et al., 1988; Chowdhury and Zhang, 1991; Yao et al., 2001; Wang et al., 2012; Michalowski, 2013; Utili, 2013). One of the main effects of cracks is that they provide preferential pathways for water flow, which significantly increases the hydraulic conductivity of the soil mass and, in turn, pore-water pressures in the soil mass (Zhang et al., 2012; Galeandro et al., 2013; Suryo, 2013). As a result, the shear strength of the soil decreases. Water infiltration into the cracked soil often starts from unsaturated conditions; thus, water retention ability and hydraulic conductivity under unsaturated conditions are important factors. The water retention ability and hydraulic conductivity of cracked soil vary with the soil suction under unsaturated conditions.
