@article{zamani_montoya_gabr_2019, title={Investigating challenges of in situ delivery of microbial-induced calcium carbonate precipitation (MICP) in fine-grain sands and silty sand}, volume={56}, ISSN={0008-3674 1208-6010}, url={http://dx.doi.org/10.1139/cgj-2018-0551}, DOI={10.1139/cgj-2018-0551}, abstractNote={ Microbial-induced calcium carbonate precipitation (MICP) is a sustainable soil improvement method with the potential for improving the engineering properties of sand and silty soils and therefore their resistance to liquefaction-inducing events. Work presented herein experimentally investigates the changes in hydraulic conductivity of fine sands and silty sands as a result of MICP treatment. In addition, numerical modeling is conducted to assess the changes in allowable injection rate and radius of influence for the delivery of the MICP process at the field scale. The hydraulic conductivity of Nevada sand and silty sand with 15% fines content decreased through MICP application with the trend of reduction being similar for both soils. Numerical modeling results show that with the progress of the MICP process, injection rates can be increased for Nevada sand, but remain unchanged for Nevada sand with 15% silt content (after MICP treatment up to a shear wave velocity about 400 m/s.) The presence of fines by itself leads to generation of higher levels of pore-water pressure during the injection process, which necessitates higher strength improvement to prevent development of excessive plastic strains. Therefore, improvement in shear strength and stiffness relative to the magnitude of the hydraulic conductivity level and its rate of change during the MICP process is a key parameter in determining the radius of treatment. }, number={12}, journal={Canadian Geotechnical Journal}, publisher={Canadian Science Publishing}, author={Zamani, A. and Montoya, B.M. and Gabr, M.A.}, year={2019}, month={Dec}, pages={1889–1900} }
 @article{zamani_montoya_2019, title={Undrained cyclic response of silty sands improved by microbial induced calcium carbonate precipitation}, volume={120}, ISSN={["1879-341X"]}, DOI={10.1016/j.soildyn.2019.01.010}, abstractNote={Loose saturated silty sand can be prone to liquefaction but improving their soil properties is challenging due to their lower permeability compared to clean sands. Microbial induced calcium carbonate precipitation (MICP) is a new, natural and sustainable soil improvement method, which can increase the shear strength and stiffness of soils. In this study, MICP treatment is applied to silty sands with fines content in the range of 0–35% and a constant preshear void ratio 0.7 ± 0.05 to observe improvement in their liquefaction resistance. The specimens are treated until reaching a shear wave velocity about 400 m/s. Cyclic direct simple shear testing is used to evaluate changes in the liquefaction resistance of untreated and MICP treated silty sands. The results show that by applying MICP the liquefaction resistance increases significantly for all fines contents tested, and the treatment efficiency depends on the level of fines content, which dictate the relative density, and the fabric governing the structure. As examples, the 35% fines content specimen has shown the highest improvement, which is related to a higher relative density at this fines content. The silty sand specimens with 5% fines content has a metastable structure which makes the soil more sensitive to cyclic loading. Although the cyclic resistance has increased by applying MICP at this level of fines content, its sensitivity to cyclic loading has remained unchanged. The results of this study demonstrate that MICP improves the cyclic strength of silty sand and can provide an alternative soil improvement method for silty sand.}, journal={SOIL DYNAMICS AND EARTHQUAKE ENGINEERING}, author={Zamani, Atefeh and Montoya, Brina M.}, year={2019}, month={May}, pages={436–448} }
 @inproceedings{zamani_liu_montoya_2018, title={Effect of microbial induced carbonate precipitation on the stability of mine tailings}, DOI={10.1061/9780784481615.024}, abstractNote={Dams and impoundments are the most conventional method for depositing mine tailings material. Regular operation of the tailings dams often increase the height of the dams, which may make them susceptible to failure. Many existing mine tailings dams are prone to slope failure and require remediation. In this study, microbial induced calcium carbonate precipitation (MICP) is presented as a new method to improve the stability of mine tailings dams against slope failure. MICP also has the potential to improve other deficiencies of the mine tailings material such as surface erosion, static liquefaction, and dynamic liquefaction. In the present study, Slope/W program is used to perform slope stability analysis and observe the effect of MICP on the static slope stability of mine tailings material. The results show an increase in the slope stability after biocementation. The level of improvement in the factor of safety against slope failure depends on the level of treatment.}, number={298}, booktitle={Ifcee 2018: case histories and lessons learned}, author={Zamani, A. and Liu, Q. W. and Montoya, B. M.}, year={2018}, pages={291–300} }
 @article{zamani_montoya_2018, title={Undrained Monotonic Shear Response of MICP-Treated Silty Sands}, volume={144}, ISSN={["1943-5606"]}, DOI={10.1061/(asce)gt.1943-5606.0001861}, abstractNote={AbstractThe effect of nonplastic fines on the undrained shear response of sand depends on many variables, including fines content, skeleton void ratio (es), interfine void ratio (ef), global void r...}, number={6}, journal={JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING}, author={Zamani, A. and Montoya, B. M.}, year={2018}, month={Jun} }