Abstract: Expansive soil in the repetitive wet-dry cycle, the volumetric expansion occurs by water absorption and contraction when the moisture is lost, and cracks are generated in the soil body. This paper summarizes the process of crack generation: Major cracks are formed, and more secondary fissures are generated, and soil body are separated by various fissures. The development of the fissures is associated with the moisture evaporation rate, gradient of moisture content, and quantity of the moisture evaporation. With the continuous development of measuring instruments, more accurate fissure development can be observed. Imaging processing method is widely used to obtain two-dimensional plane fissure distribution. Spatial fissure distribution can be obtained by processing images and three-dimensional modeling. The review of several fissure seepage models is introduced, and their advantages and disadvantages are discussed. The equivalent continuum seepage model is widely used.

Key words: Fissured Expansive Soils, Seepage Flow, Seepage Model, Research Progress