Unconfined Compressive Strength of MICP-Treated Black Cotton Soil

Abstract

AbstractExpansive soil which is found in several parts of India possesses high swelling and shrinkage properties. The volume change and uplift pressure generated in these soil deposits cause severe damage to the lightweight structures and pavements. In order to mitigate the problems associated with expansive soils, it is necessary to stabilize this soil. Among all the stabilization techniques, microbial induced calcite precipitation (MICP) is a sustainable biological ground improvement technique that is capable of altering and improving the engineering properties of black cotton soil. The application of microbiological processes for improvement of engineering properties of soil offers sustainable, cost-effective, non-disruptive ground improvement for a variety of geotechnical problems. This paper presents the results of a study in which microbiological processes were used to alter the properties of expansive soil. Microbial induced calcite precipitation (MICP) was achieved using the microorganism Bacillus Pasteurii. The microbes in liquid medium and cementation media were introduced to the soil specimen. The soil specimens were kept for different reaction periods (0, 3, 7 and 14 days) with different percentages of microbes. From the study, Bacillus Pasteurii had shown major influence for all percentages of microbe and reaction times on unconfined compressive strength of expansive soil.KeywordsMICPExpansive soilSoil stabilizationEngineering propertiesUnconfined compressive strength