Research on the protection of expansive soil slopes under heavy rainfall by anchor-reinforced vegetation systems

An anchor-reinforced vegetation system (ARVS) is a new type of flexible slope protection system. ARVSs are composed of vegetation, anchors and high-performance turf reinforcement mats (HPTRMs) and can maintain the stability of expansive soil slopes while producing superior ecological effects. Through in situ comprehensive monitoring and comparative analyses, we systematically discuss the impact of heavy rainfall on ARVS-protected expansive soil slopes during the local wet season in Nanning. The results show that during the local wet season, the soil temperature and water content in vegetation-covered areas are lower than those in bare areas. The soil temperatures in different areas on the expansive soil slopes decrease with increasing depth. The ARVSs significantly affected the regulation of water transport and soil temperature, which limited soil deformation in different directions. The subsequent heavy rainfall would cause greater deformation of the expansive soil slope when less antecedent rainfall fell. Low-intensity and long-duration heavy rainfall events have greater negative impacts on expansive soil slopes than high-intensity and short-duration rainfall events. Under the action of severe rainfall-evaporation, expansive soil slopes protected by ARVSs can maintain stability. •An anchor-reinforced vegetation system (ARVS) is used in the protection of expansive soil slope.•The effect of anchor-reinforced vegetation system on expansive soil slope is tested in the field.•The impact of heavy rainfall on ARVS-protected expansive soil slopes during the local wet season is discussed.