{"title":"Reactive transport modeling of microbial-induced calcite precipitation treatment through shallow underwater injection","authors":"","doi":"10.1016/j.compgeo.2024.106601","DOIUrl":null,"url":null,"abstract":"<div><p>A reactive transport model has been developed to simulate the bio-chemo-hydro-mechanical coupled process associated with soil improvement by Microbially Induced Calcite Precipitation (MICP) in shallow submerged conditions. Besides including the key processes of bacterial attachment and decay, urea hydrolysis, and CaCO<sub>3</sub> precipitation, this study demonstrates the necessity to account for variable fluid density and associated gravity-driven flow, to select the appropriate boundary conditions by including the water adjacent to the sand as a separate domain and to include bacterial detachment. After fitting the parameters describing bacterial attachment, detachment, decay, and the reaction kinetics, the final precipitated calcium carbonate from the numerical simulations exhibits a decent agreement with the experimental results presented by <span><span>Montoya et al. (2021)</span></span> in terms of quantity and distribution pattern. However, still differences exist between the simulated and measured shear wave velocity (<span><math><mrow><msub><mi>V</mi><mi>s</mi></msub></mrow></math></span>) and its increment through multiple treatment cycles, which suggests a more complex coupling between porosity, hydraulic conductivity, small strain stiffness, and the type or pore habit and heterogeneity of the distribution of the precipitated CaCO<sub>3</sub>. The limitations of the model and directions for further development to capture the complexity of this coupled process are discussed.</p></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3000,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computers and Geotechnics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0266352X24005408","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS","Score":null,"Total":0}
引用次数: 0
Abstract
A reactive transport model has been developed to simulate the bio-chemo-hydro-mechanical coupled process associated with soil improvement by Microbially Induced Calcite Precipitation (MICP) in shallow submerged conditions. Besides including the key processes of bacterial attachment and decay, urea hydrolysis, and CaCO3 precipitation, this study demonstrates the necessity to account for variable fluid density and associated gravity-driven flow, to select the appropriate boundary conditions by including the water adjacent to the sand as a separate domain and to include bacterial detachment. After fitting the parameters describing bacterial attachment, detachment, decay, and the reaction kinetics, the final precipitated calcium carbonate from the numerical simulations exhibits a decent agreement with the experimental results presented by Montoya et al. (2021) in terms of quantity and distribution pattern. However, still differences exist between the simulated and measured shear wave velocity () and its increment through multiple treatment cycles, which suggests a more complex coupling between porosity, hydraulic conductivity, small strain stiffness, and the type or pore habit and heterogeneity of the distribution of the precipitated CaCO3. The limitations of the model and directions for further development to capture the complexity of this coupled process are discussed.
期刊介绍:
The use of computers is firmly established in geotechnical engineering and continues to grow rapidly in both engineering practice and academe. The development of advanced numerical techniques and constitutive modeling, in conjunction with rapid developments in computer hardware, enables problems to be tackled that were unthinkable even a few years ago. Computers and Geotechnics provides an up-to-date reference for engineers and researchers engaged in computer aided analysis and research in geotechnical engineering. The journal is intended for an expeditious dissemination of advanced computer applications across a broad range of geotechnical topics. Contributions on advances in numerical algorithms, computer implementation of new constitutive models and probabilistic methods are especially encouraged.