Soil cementation and solidification, based on microbially induced calcium carbonate precipitation (MICP) technology, has emerged as research hotspots in geotechnical engineering and geological engineering since the 21st century. In this research, the reinforcement mechanism of MICP technology and the research status of the engineering application and the reinforcement effect and application practice are systematically described and reviewed. The results show that the strength of the site after MICP solidification shows an obvious non-uniformity, and the distribution of calcium carbonate content decreases with depth. In desert environment, the calcium carbonate coating induced by in-situ extraction of bacteria demonstrates superior strength and stability to the traditional Bacillus pasteurelli. The application of new MICP technology, such as microbial cement and microbial brick, shows promising prospects in terms of strength and durability, and new vitality into the realization of China’s double carbon goal. Addressing the factors affecting the precipitation characteristics of calcium carbonate by MICP technology, the uniformity of calcium carbonate distribution at field scale is enhanced, the durability of calcium carbonate skeleton under seasonal changes ensured, and curing efficiency under different environments improved, which should all be prioritized in future research.

Microbial silica sand pile is a kind of energy-saving and environmentally friendly small diameter short pile prepared by microbially induced calcium carbonate precipitation (MICP) technology. In this study, an indoor model box simulation test is conducted to analyze the bearing performance advantages of microbial siliceous sand piles, the distribution characteristics of pile side friction resistance, and the load transfer characteristics. The following conclusions are drawn: (1) The siliceous sand piles obtained through microbial solidification technology exhibits a good curing effect, with the unconfined compressive strength of the piles reaching 436.8 kPa. (2) The bearing capacity of single pile of microbial silica sand increases with pile length. When the pile length L is 560 mm, the ultimate bearing capacity of single pile reaches 0.81 kN, with a settlement of pile top at 20.06 mm. Upon insertion into the bearing layer, the bearing capacity of the single pile can reach 1.06 kN, representing a 34.6%. (3) The axial force of microbial coral sand pile decreases with increasing depth. Due to the short pile, the lateral friction resistance of the pile is positive, and the friction resistance increases rapidly in the 0-20 cm section, demonstrating noticeable soil squeezing effect. As the 20-40 cm section decreases from increase, the calcium carbonate skeleton is liable to break, resulting in a decrease in horizontal effective stress around the pile and a slowdown in the increase of pile side friction. (4) The ultimate bearing capacity of the soft soil-microbial silica sand pile composite foundation is approximately 41.3 kPa, 24.8% improvement over that of the untreated soft soil foundation. The test results can lay the groundwork for the engineering application of microbial siliceous sand pile.