Model test study on the protection of expansive soil slope with polymer waterproof coating

Polymer Waterproof Coating (PWC) is proposed to protect expansive soil slopes. Three groups of slope test models are developed to compare the efficiency of PWC, and the laws of water content, pore water pressure, soil deformation, and slope surface morphology change under repeated cycles of precipitation-evaporation environment are monitored and analyzed. The mechanism and effect of PWC protection on the expansive soil slope are discussed. The test results show that cyclic precipitation-evaporation has a significant impact on the water content, deformation, and slope surface shape of shallow layer of expansive soil slope. The change of water content and pore water pressure of slope caused by rainfall infiltration has hysteresis. The PWC-protected slope has significantly less soil deformation and water change than bare slope. The PWC protective layer blocks the water exchange between inside and outside the slope, keeping the slope water in a "dynamic and stable" state and inhibiting the slope surface cracking. The PWC protective layer significantly reduces the erosion of slope surface due to rainwater and has a significant effect on improving the integrity and strength of the slope soil. The PWC protection slope continues to have great stability even after numerous simulations of extremely harsh climates.