Ecological flexible protection method of expansive soil slopes under rainfall

In this study, a new ecological slope protection method – anchor-reinforced vegetation system (ARVS) – was applied to a newly excavated expansive soil slope. To explore the effect and mechanism of ARVS protection of newly excavated expansive soil slopes, expansive soil slopes with three different protection methods (bare slopes, grassed slopes and ARVS slopes) were built. Continuous natural rainfall tests and artificial rainfall tests were carried out. The results showed that compared with the bare slope and the grassed slope, the ARVS could effectively adjust the moisture and heat balance of newly excavated expansive soil slopes and achieve a satisfactory soil and water conservation performance. Under different rainfall intensities, the run-off and soil loss rates of the ARVS-protected slope were the smallest. Under the combined action of vegetation, high-performance turf reinforcement mats and anchors, the ARVS provided a superior erosion resistance. The higher the rainfall intensity, the more significant the anti-erosion effect of the ARVS compared with that of grass protection technology. The ARVS could also effectively limit the vertical and horizontal deformation of newly excavated expansive soil slopes. Therefore, the ARVS could effectively reduce the negative influence of the atmospheric environment on newly excavated expansive soil slopes and provide a new solution for shallow protection of newly excavated expansive soil slopes.