Seepage and Stability Analysis of Fissured Expansive Soil Slope Under Rainfall

Expansive soil is characterized by fissure development, thus making expansive soil slope unstable under rainfall. In this study, under the background of Yanji expansive soil cutting slope, the seepage field and stability evolution characteristics of fissured expansive soil slope under rainfall were investigated through numerical simulation. The transient water migration of slope at different fissure depths was simulated using the finite element method. In accordance with unsaturated strength coupling theory and with the use of limit equilibrium method, the slope stability was obtained, and the supporting effect of bolt length, angle and reinforcement position on expansive soil slope under rainfall was investigated. As revealed by the results, fissures increased the influence range of rainfall infiltration, and the depth of fissures was found as a vital factor to control the seepage and stability of slope. Moreover, the expansive soil slope landslide induced by rainfall had the characteristics of shallow depth, small range and gradual process. The control method of expansive soil slope landslide based on bolt reinforcement was proposed. The engineering examples and slope stability monitoring results suggested that reasonably using bolt reinforcement technology could effectively inhibit the development of expansive soil slope fissures and reduce the effect of rainfall on the stability of expansive soil slope. The proposed method is capable of providing a theoretical reference for the prevention and control of instability disaster of expansive soil slope.