Experimental study on water and soil retention of slopes by MICP surface mineralization combined with vegetation

The ecological restoration is popular by means of grid beams on slopes with earth fill and plant. The rainfall erosion tests are carried out on the slope models with different slope gradients, rainfall intensities, microbial mineralizations and vegetation coverages, so that the feasibility is explored by using the microbial mineralization and vegetation restoration on slope surface. The results show that the increase of the slope gradient will aggravate erosion of the filled soil, and the increase of the rainfall intensity will lead to the advance of the failure time. The surface mineralization can improve slope runoff, and the average runoff rate of pure soil and surface mineralized soil is 0.59 L/min and 0.64 L/min, respectively, and the runoff after the surface mineralization is more stable. The mineralization enhances erosion resistance of the soil by strengthening the loose soil particles on the slope. The larger the vegetation coverage is, the smaller the slope erosion modulus is. Compared with that of the pure soil, the erosion of the improved slope soil is reduced by 58%~72% with vegetation coverage, and 86% after the surface mineralization, and 99% under the surface mineralization plus vegetation. The soil conservation effect of the mineralization is better than that with the vegetation only. The rehabilitation effect in the ecological restoration of slopes is remarkable by use of the soil surface mineralization combined with the vegetation, which is of certain practical engineering values.