Application of MICP in ameliorating erosion resistance of soil on reservoir banks

Abstract Regulating reservoirs with clay slopes are prone to severe erosion caused by wind‐wave actions and water‐level fluctuations. Conventional bank protection methods often rely on rigid structures, which can adversely affect ecosystems. This study explores the use of microbially induced carbonate precipitation (MICP) for soil stabilization to enhance the erosion resistance of clay slopes and support plant growth. Through unconfined compressive strength (UCS) tests and seed germination trials, an optimal MICP treatment formula was identified. Using calcium acetate as the calcium source, with a cementation solution concentration of 0.5 mol/L and a reagent dosage of 23%, the UCS increased by 235.3% (from 20.5 to 68.7 kPa). Euphrasia pectinate Ten and Sesbania cannabina were found to be suitable plant species for MICP‐treated soil, achieving germination rates of 45% and 30%, respectively. Disintegration and wave erosion tests demonstrated that the disintegration rate of MICP‐treated specimens decreased from 23.1% to 0%, and the erosion mass rate decreased from 1.5% to 0.2%. Field tests further validated the effectiveness of MICP, with treated slopes exhibiting no erosion and demonstrating penetration and shear strengths of 47.9 kPa and 114.5 kPa, respectively—2.5 and 3.2 times higher than those of untreated slopes. The MICP process facilitates calcium carbonate deposition, reduces pore space, and enhances interparticle bonding. Calcium carbonate crystals derived from calcium acetate exhibited stronger adhesion than those formed from calcium chloride. Filamentous organic matter was closely adhered between soil particles, further enhancing the ductility and resistance to hydraulic erosion. Additionally, acetate ions reduce MICP toxicity to plants and enhance microbial activity and nutrient cycling, creating more favorable conditions for plant growth.