Abstract:Microbially induced calcium carbonate precipitation is a new and sustainable technology, which includes bioaugmentation and biostimulation approaches. However, the existing related research is mostly limited to bioaugmentation approach, and there is relatively little research on biostimulation approach, especially large-scale experiments. In this study, the surface soil along Jialing River in Chongqing is taken as the research object, and the influence of different reinforcement degrees on the shear characteristics of large-scale samples is explored based on biostimulation approach. In addition, the distribution of calcium carbonate content in different directions was also determined. The results show that the stress-strain relationship of the specimen before and after strengthening has changed from strain hardening to brittle fracture and strain softening. In terms of dilatancy, the specimen shows a phenomenon of shear shrinkage before reinforcement, while the specimen shows a slight shear shrinkage first and then a phenomenon of shear expansion after reinforcement. After reinforcement, the shear strength of the specimen has been greatly improved. The calcium carbonate content in the sample decreases with the increase of the distance from the top surface of the sample, and the calcium carbonate content in the sample presents a distribution pattern of high in periphery part and low in middle part. The results of this study can provide reference for the application of biostimulation approach in field tests.