Evaluation of Factors Affecting Erodibility Improvement for MICP-Treated Beach Sand

Document Type

Article

Publication Date

3-1-2021

Abstract

Microbially induced calcite precipitation (MICP) was used to treat several sandboxes filled with naturally occurring beach sand collected from Atlantic Beach, Florida. A surface-spray/percolation technique was used to treat these sandboxes where a relatively high-concentration bacteria solution and high-concentration calcium chloride/urea solutions were applied directly to the boxes' surfaces. Several different treatment combinations were tested whereby bacterial optical density, bacteria/urea/calcium chloride volume relative to pore volume, and bacteria/urea/calcium chloride ratio were manipulated. Treated sandboxes were tested for erodibility using a pocket erodometer. In addition, sandboxes were dissected after erosion testing to examine crust depth. Results showed that higher optical densities, higher bacteria quantities relative to void volume, and higher bacteria quantities relative to urea led to lower erodibility and greater crust depth. When MICP constituent quantities were maximized to give the best erosion/crust-depth results, erodibility improvements began to approach what may be considered adequate erosive resistance. Further investigation is required to better classify this behavior more quantitatively.

Publication Title

Journal of Geotechnical and Geoenvironmental Engineering

Volume

147

Issue

3

Digital Object Identifier (DOI)

10.1061/(ASCE)GT.1943-5606.0002481

ISSN

10900241

E-ISSN

19435606

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