Experimental Study of the Mitigation of Soil Internal Erosion by Microbially Induced Calcite Precipitation

Abstract

In this study, a series of rigid-wall downward erosion tests were conducted to investigate the mitigation effect of microbially induced calcite precipitation (MICP) on soil internal erosion. Sand-kaolin mixture was used in this study, which proves to be internally unstable in terms of particle size distribution. Binary mixture was prepared using dry tamping method. Bacteria and cementation solutions were injected into samples at several phases. For comparison, control samples without MICP treatment were prepared. All samples were subjected to downward seepage flow with incremental flow rates. Evolutions of hydraulic conductivity, effluent kaolin concentration, and total erosion mass were measured against hydraulic gradient and shear stress. Results confirmed that, with MICP treatment, both critical hydraulic gradient and shear stress were significantly increased and erosion mass was reduced under the same hydraulic conditions. © 2014 American Society of Civil Engineers.