The Effect of the Coefficient of Uniformity on the Dynamic Properties of MICP-Treated Sands
Publication: Geo-Congress 2023
ABSTRACT
Microbially induced carbonate precipitation (MICP) is a bio-mediated ground improvement technique that can increase the liquefaction resistance of loose granular deposits. Previous researchers have acknowledged the possible amplification of ground motions due to the improvement in soil stiffness from MICP-treatment. To further elucidate the response of MICP-treated soils to cyclic loading and its impact on ground motion characteristics, an understanding of the shear modulus reduction and energy dissipation as a function of shear strain is required. Modulus reduction and damping (MRD) curves are a key input for site response analysis, which evaluates the influence of a local soil deposit on the characteristics of seismic waves. We investigate the influence of the coefficient of uniformity (Cu) on MRD curves of sands treated to a moderate level of cementation. The dynamic properties of the untreated and MICP-treated sands were evaluated through resonant column testing. Results indicate that an increase in Cu leads to greater reduction of the MICP-treated normalized shear modulus curve compared to that of the untreated soil. Additionally, the minimum calcium carbonate content and MICP uniformity was observed to influence the reduction behavior shown in MRD curves obtained from resonant column testing. These preliminary findings are important for seismic analysis and design because the Cu of MICP-treated soils and the MICP-treatment uniformity influence dynamic soil properties and will likely affect the response of MICP-treated soils to cyclic loading; however, further research is needed to fully understand the observed behavior.
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REFERENCES
Darby, K. M., Hernandez, G. L., DeJong, J. T., Boulanger, R. W., Gomez, M. G., and Wilson, D. W. (2019). “Centrifuge model testing of liquefaction mitigation via microbially induced calcite precipitation.” Journal of Geotechnical and Geoenvironmental Engineering, 145(10).
Darendeli, M. B. (2001). Development of a new family of normalized modulus reduction and material damping curves. The University of Texas at Austin.
DeJong, J. T., Mortensen, B. M., Martinez, B. C., and Nelson, D. C. (2010). “Bio-mediated soil improvement.” Ecological Engineering, 36(2), 197–210.
DeJong, J., Gomez, M. G., San Pablo, A. C. M., Graddy, C. M. R., Nelson, D. C., Lee, M., Ziotopoulou, K., El Kortbawi, M., Montoya, B., and Kwon, T.-H. (2022). “State of the Art: MICP soil improvement and its application to liquefaction hazard mitigation.” Proceedings of the 20th International Conference on Soil Mechanics and Geotechnical Engineering, Sydney, Australia.
Feng, K., and Montoya, B. M. (2017). “Quantifying Level of Microbial Induced Cementation for Cyclically Loaded Sand.” Journal of Geotechnical and Geoenvironmental Engineering, 143(6).
Kramer, S. L. (1996). Geotechnical Earthquake Engineering, Prentice Hall, Englewood Cliffs, N.J., 653.
Lee, M., Gomez, M. G., El Kortbawi, M., and Ziotopoulou, K. (2021). “Effect of light biocementation on the liquefaction triggering and post- triggering behavior of loose sands.” Journal of Geotechnical and Geoenvironmental Engineering, 148(1).
Menq, F. Y. (2003). Dynamic properties of sandy and gravelly soils. The University of Texas at Austin.
Montoya, B. M., DeJong, J. T., and Boulanger, R. W. (2013). “Dynamic response of liquefiable sand improved by microbial-induced calcite precipitation.” Géotechnique 63(4), 302–312.
Na, K., Cabas, A., and Montoya, B. (2022). “Design of MICP treatment accounting for changes in seismic site response and liquefaction potential.” Proceedings from ASCE GeoCongress 2022, Charlotte, North Carolina.
Na, T. K., Cabas, A., and Montoya, B. M. (2022). “Resonant column testing procedure for microbial induced carbonate precipitated sands.” Geotechnical Testing Journal, (in review).
Nafisi, A., Montoya, B. M., and Evans, T. M. (2020). “Shear strength envelopes of bio-cemented sands with varying particle size and cementation level.” Journal of Geotechnical and Geoenvironmental Engineering, 146(3).
Stokoe, K. H., Darendeli, M. B., Andrus, R. D., and Brown, L. T. (1999). “Dynamic soil properties: laboratory, field and correlation studies.” Earthquake geotechnical engineering, 811–845.
Zamani, A., and Montoya, B. M. (2019). “Undrained Cyclic Response of Silty Sand Improved by Microbial Induced Calcium Carbonate Precipitation.” Soil Dynamics and Earthquake Engineering, 120, 436–448.
Zamani, A., Xiao, P., Baumer, T., Carey, T. J., Sawyer, B., DeJong, J. T., and Boulanger, R. W. (2021). “Mitigation of liquefaction triggering and foundation settlement by MICP treatment.” Journal of Geotechnical and Geoenvironmental Engineering, 147(10).
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Published In
Geo-Congress 2023
Pages: 12 - 20
History
Published online: Mar 23, 2023
ASCE Technical Topics:
- Curvature
- Dynamic properties
- Engineering fundamentals
- Geomechanics
- Geometry
- Geotechnical engineering
- Geotechnical investigation
- Ground motion
- Material mechanics
- Material properties
- Materials engineering
- Mathematics
- Mechanical properties
- Shear modulus
- Soil analysis
- Soil dynamics
- Soil mechanics
- Soil modulus
- Soil properties
- Structural behavior
- Structural engineering
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