The objective of this collaborative project is to explore the potential of ureolytic calcite precipitation as a practical means of improving the capacity of vertical support elements for foundations in sands and silts. Enhancement of vertical elements for foundation support holds promise as the first practical application of biologically induced carbonate precipitation in geotechnical engineering. A key element of the work is exploring the use of agriculturally-derived urease enzyme as the catalyst for calcite precipitation rather than microbially-derived urease employed in all calcite precipitation studies reported to date. The limited extent of the improvement zone required to enhance vertical foundation support elements mitigates problems associated with mass stabilization of soil by induced carbonate precipitation. The use of agriculturally-derived urease can further mitigate some of the problems encountered in mass stabilization and extend the range of soils that can be stabilized by induced carbonate precipitation into the silt-sized particle range.
The primary broader impact of this project is associated with the development of a practical application of bio-mediated ground improvement. Developing a practical application for this technology (bio-mediated carbonate precipitation) is a potentially transformative accomplishment, accelerating the development of biogeochemical ground improvement techniques and motivating further innovative developments in the emerging field of biogeotechnical engineering. Extending the applicability of bio-mediated carbonate precipitation into the silt-sized particle range would also have, in and of itself, a broad impact on both the broad field of geotechnical engineering and the emerging sub-discipline of biogeotechnical engineering. The project will also make contributions to training and education of geotechnical professional through support of graduate student research assistants and, in particular, through training and education of new researchers knowledgeable and competent in the techniques and procedures employed in biogeotechnical engineering that are not usually employed in traditional geotechnical research.
