Abstract: Collapsing gully is the most serious soil erosion phenomenon in granite region in China. Slope surface protection is an important measure to control the erosion of collapsing gully soil. Collapsing gully soil in Guanqiao town in Anxi county, one of the most developed areas in Fujian Province, was investigated in this study and a model experiment was carried out to investigate the feasibility of the application of microbially induced carbonate precipitation (MICP) technology on the slope surface erosion protection. The MICP spraying technology was used to treat the surface of the collapsing gully soil slope. Then, the slope was flushed by an artificial rainfall simulation system. The impacts of the MICP technology on the amount of substance in the effluent and erosion depth on the slope surface were analyzed. The results show that the amount of matter in the effluent of treated slope decreased from 7648.43 g to 266.61 g, which was 96.51% lower than that before treatment; the erosion depth decreased from 60 mm to no obvious erosion except for individual erosion hole compared with untreated slopes. The current work shows that the MICP technology can effectively reduce the erosion of residual soil slope in collapsing gully region.

Key words: microbial induced carbonate precipitation (MICP), collapsing erosion, soil cover, rainfall simulation, surface erosion