Sand solidification of earth-rock dams is the key to flood discharge capacity and collapse prevention of earth-rock dams. It is urgent to find an economical, environmentally friendly, and durable sand solidification technology. However, the traditional grouting reinforcement method has some problems, such as high costs, complex operations, and environmental pollution. Enzyme-induced calcium carbonate precipitation (EICP) is an anti-seepage reinforcement technology emerging in recent years with the characteristics of economy, environmental protection, and durability. The erosion resistance and shear strength of earth-rock dams solidified by EICP need further verification. In this paper, EICP-solidified standard sand is taken as the research object, and EICP-cemented standard sand is carried out by a consolidated undrained triaxial test. A two-stage pouring method is adopted to pour samples, and the effects of dry density, cementation times, standing time, and confining pressure on the shear strength of cemented standard sand are emphatically analyzed. The relationship between cohesion, internal friction angle, and CaCO₃ formation was analyzed. After the optimal curing conditions are obtained through the triaxial shear strength test, the erosion resistance model test is carried out. The effects of erosion angle, erosion flow rate, and erosion time on the erosion resistance of EICP-solidified sand were analyzed through an erosion model test. The results of triaxial tests show that the standard sand solidified by EICP exhibits strain softening, and the peak strength increases with the increase in initial dry density, cementation times, standing time, and confining pressure. When the content of CaCO₃ increases from 2.84 g to 12.61 g, the cohesive force and internal friction angle change to 23.13 times and 1.18 times, and the determination coefficients reach 0.93 and 0.94, respectively. Erosion model test results indicate that the EICP-solidified sand dam has good erosion resistance. As the increase in erosion angle, erosion flow rate, and erosion time, the breach of solidified samples gradually becomes larger. Due to the deep solidification of sand by EICP, the development of breaches is relatively slow. Under different erosion conditions, the solidified samples did not collapse and the dam broke. The research results have important reference value and scientific significance for the practice of sand consolidation engineering in earth-rock dams.

Aeolian sand is susceptible to wind and water erosion, which seriously restricts the ecological restoration and sustainable development in desert areas. Traditional solidification methods have characteristics of high cost, easy pollution, and unstable solidification. Enzyme-induced calcium carbonate precipitation (EICP) is an emerging method that has advantages in terms of cost-effectiveness, environmental friendliness, and durability, and, especially when coupled with fiber reinforcement (FR), it can significantly prevent brittle fracture. In this paper, ultraviolet (UV) erosion and freeze–thaw (FT) erosion tests were conducted to investigate the anti-erosion capacity of aeolian sand solidified by EICP and basalt fiber reinforcement (BFR) or wool fiber reinforcement (WFR). According to the analysis of the variation laws of sample appearance, quality losses, and unconfined compressive strength (UCS) during the UV and FT erosion process, the erosion mechanism was revealed, and the UCS models considering the damage effects were established. The research results indicated that the UCS of aeolian sand solidified by MICP and FR was significantly improved under UV and FT erosion. The strength loss rates of aeolian sand solidified by EICP, EICP–BFR, and EICP–WFR reached 45.4%, 46.6%, and 51.6%, respectively, under 90 h UV erosion. When the FT cycles reached 8, the strength loss rate of aeolian sand solidified by EICP, EICP–BFR, and EICP–WFR attained 41.0%, 49.2%, and 55.8%, respectively. The determination coefficients of the UCS models were all greater than 0.876, indicating that the experimental results were in good agreement with the predicted results, verifying the reliability of the established models. The research results can offer reference values for windproof and sand fixation in desert areas.