Mechanical Behavior of Microbially Induced Calcite Precipitation Cemented Sand

New sustainable ground improvement techniques have been recently required for applications in onshore and offshore geotechnical structures. The Microbiological Induced Calcite Precipitation (MICP) method is a ground improvement technique that results from a natural biogeochemical process in order to create a soil cemented framework. The biocementation resulted from this method has been shown to produce a reasonable increment in soil’s mechanical properties such as strength and stiffness. This study focused on evaluating the mechanical behavior of a biocemented uniform sand by using the MICP method. Three different cemented levels were produced in a laboratory scale by varying the amount of a chemical solution (cementation solution) percolated through the specimens. The experimental outcome from a set of triaxial tests performed at three different confining pressures (100 kPa, 200 kPa, and 400 kPa) demonstrated that the MICP method produced an increment in strength with a peak in the deviatoric stress when compared to the uncemented soil, changing the cohesion intercept from nearly 0 kPa to 75 kPa. Furthermore, the stress-dilatancy response indicated that a fully structural degradation is achieved at large plastic strains, differently from what is usually observed in chemically artificially cemented blends, like soil–cement and soil–lime.