A critical review on soil stabilization using bacteria

Abstract

To gratify the escalating need for land, it is vital to improve the lands with loose weak soils. These problematic loose soils can be optimized by nurturing the shear strength, lessening the time and potential for settlement and also reducing the hydraulic conductivity of soil, by using Microbial induced calcite precipitation (MICP) process. This process of MICP is carried out by adding bacterial solution into soil specimen which is continued with inoculation of cementation reagents having urea and one calcium salt (CaCl2) for enormous times. As a result, calcite precipitate (CaCO3) is formed in the soil and stabilize the soil. In this study, a number of factors that are responsible for better formation of calcite precipitate are examined. This process mainly depends upon soil type, bacteria species, concentration of cementation solution, injection methods and also on pH, temperature conditions and curing period. The aim of this paper is to review the main factors that influence the MICP process, such as soil properties, bacterial species, nutrients, concentration of cementation solution, pH, temperature and injection methods.