Field Application of the Microbially Induced Calcium Carbonate Precipitation on a Coastal Sandy Slope

Sandy slopes and levees in coastal areas are subjected to heavy rains and large storm events, which makes such structures susceptible to surface erosion and failure. Microbially induced calcium carbonate precipitation (MICP) is an emerging soil improvement technique that has shown promising results in scour reduction, liquefaction mitigation, and dust control, among other applications. This method utilizes natural soil bacteria to hydrolyze urea and induce calcium carbonate to bond soil particles together and improve soil matrix's properties. The study presented herein discusses the implementation of the MICP treatment using surface percolation on a 1 m×8 m plot located on a coastal sandy slope. To make the field application more economically feasible, instead of using laboratory-grade chemicals, industrial-grade urea and calcium chloride were used for the treatments. At the end of the treatment, dynamic cone penetration (DCP) tests were performed on the treated plot and mass of calcium carbonate samples were taken from different elevations along the slope to have an estimation of the improvement of soil and precipitation distribution pattern with depth.