Abstract: In order to investigate the performance and mechanism of expansive soil slope with soilbags under the effect of raining-insolation cycles, a series of laboratory model tests on the expansive soil slope was conducted. The displacement of the reinforced slope, the slope erosion and rainfall infiltration were observed and analyzed, which were compared with expansive soil slope without reinforcement. The experimental results showed that under the action of raining-insolation cycles, the surface of expansive soil slope without reinforcement would develop cracks, which was further prone to soil loss. The soilbags performed well as a protection layer and a filter of soil particles, which could reduce the loss of soil in the bag and the underlying soil, and maintain the stability of the slope. In addition, soilbags had a good restraining effect on the expansive soil, which can effectively restrain its expansive deformation and reduce the possibility of slope instability. Furthermore, soilbags had a good drainage effect, so that rainwater could be quickly discharged through the gap between geotextile bags, and thus to ensure a relatively small increase of water content in the slope.

Key words: soilbags, expansive soil, model test, rainfall-insolation cycle