Experimental study on Microbially Induced Calcite Precipitation for expansive soil stabilization

Microbially induced carbonate precipitation (MICP) is extensively discussed as a promising topic for ground stabilization. The practical effect of stabilizing the expansive soil is presented in this paper with a logical process from the bacterial activity to the treatment technology. Temperature, pH, shaking frequency, and inoculation amount are discussed to evaluate the bacterial activity. The physic-mechanic properties are also evaluated to discuss the effect of the MICP process on expansive soil. Results indicate that the MICP method achieves the mitigation of expansion. The treated soil has a low proportion of fine particles (< 5 mu m), the plasticity index significantly decreases, and strength values improve much. MICP process has a significant cementation effect on the soil matrix. Moreover, the infiltration model test presents the coating effect on the topsoil. According to the relation between the CaCO3 content and the treatment effect, the topsoil has better treatment than the deeper soil.

Automated summary

Microbially induced carbonate precipitation (MICP) is a promising topic for ground stabilization. This paper presents the practical effect of stabilizing expansive soil using MICP, discussing the bacterial activity and the effect on soil properties. The results show that MICP method mitigates soil expansion, reduces fine particles, and improves strength values. The infiltration model test demonstrates the coating effect on the topsoil. The topsoil also shows better treatment than the deeper soil based on CaCO3 content and treatment effect.