ASCE has honored Pegah Ghasemi, Ph.D., A.M.ASCE, and Brina M. Montoya, Ph.D., P.E., M.ASCE, with the 2023 Collingwood Prize for the paper “Field Implementation of Microbially Induced Calcium Carbonate Precipitation for Surface Erosion Reduction of a Coastal Plain Sandy Slope,” Journal of Geotechnical and Geoenvironmental Engineering, July 2022. 

The authors present a study that demonstrates design steps, implementation, and results of the field application of microbially induced carbonate precipitation (MICP). Three implementation systems were designed and tested in a side-by-side experiment that aimed to reduce the surface erosion of a coastal sandy slope. In situ test results on MICP-treated areas demonstrated significant erosion resistance and strength improvement after the field experiment. The stabilized soil was monitored for about a year and the permanence of the MICP-treated soil against temperature fluctuations, heavy rain, freeze/thaw, a hurricane, and strong wind was verified. 

In the end, numerical sensitivity analyses were performed to extend the results of this study to soils with different grain size and particle size distributions. The results of this study can be used as groundwork for future MICP field implementations. Three proposed treatment systems can be used in a wide range of soil stabilization projects. Some of the unique contributions to the study consist of implementation methods specifically designed for surface erosion reduction, quantitative surface erosion assessment in situ, and an extended monitoring period to assess the durability of the treated soil. The sensitivity analysis also provides a unique contribution to future field applications in unsaturated soil conditions.

The Collingwood Prize is awarded to the author or authors, under 35 years of age, of a paper describing an engineering project with which the author is directly connected, or recording investigations contributing to engineering knowledge to which the author has contributed some essential contributions and which contains a rational digest of results.