{"title":"Reducing non-cohesive soil erodibility through enzyme-induced carbonate precipitation","authors":"Yingzheng Zhou, Dawei Guan, Liang Cheng, Yee-Meng Chiew, Jinhai Zheng","doi":"10.1007/s11440-024-02415-8","DOIUrl":null,"url":null,"abstract":"<div><p>Enzyme-induced carbonate precipitation (EICP), which precipitates calcium carbonate within the soil matrix to cement the granular grains, presents a promising bio-mediated approach for scour countermeasures. This study explores the erosion performance of bio-cemented sand in a closed-conduit flume system, investigating the effectiveness of EICP in mitigating scour and reducing erodibility. Various parameters such as curing duration, cementation degrees and urease activities are examined to understand their influence on erosion behaviors. Furthermore, the study incorporates the analysis of calcium carbonate content and crystal microstructure to provide a better understanding on the EICP mechanism in scour mitigation. These results highlight the critical role of the interaction between calcium carbonate content and crystal features in determining the effectiveness of erodibility reduction. As the precipitated amount increases, the cemented soil exhibits enhanced hydraulic erosion resistance, with the erosion mode shifting from particle erosion and aggregated detachment to chunk fracture. In other words, the mode of sediment transport essentially is affected by the variations in crystal size, crystal quantities and deposited morphology. Two predictive formulas for threshold Shields parameter and erosion rate are also developed. Notably, the cemented soil could maintain its stability under an elevated flow of 4 m/s under an EICP treatment with 1 M of urea and calcium chloride, and a curing duration of 24 h. These findings are anticipated to serve as a valuable theoretical foundation for engineering applications.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.6000,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Geotechnica","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s11440-024-02415-8","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Enzyme-induced carbonate precipitation (EICP), which precipitates calcium carbonate within the soil matrix to cement the granular grains, presents a promising bio-mediated approach for scour countermeasures. This study explores the erosion performance of bio-cemented sand in a closed-conduit flume system, investigating the effectiveness of EICP in mitigating scour and reducing erodibility. Various parameters such as curing duration, cementation degrees and urease activities are examined to understand their influence on erosion behaviors. Furthermore, the study incorporates the analysis of calcium carbonate content and crystal microstructure to provide a better understanding on the EICP mechanism in scour mitigation. These results highlight the critical role of the interaction between calcium carbonate content and crystal features in determining the effectiveness of erodibility reduction. As the precipitated amount increases, the cemented soil exhibits enhanced hydraulic erosion resistance, with the erosion mode shifting from particle erosion and aggregated detachment to chunk fracture. In other words, the mode of sediment transport essentially is affected by the variations in crystal size, crystal quantities and deposited morphology. Two predictive formulas for threshold Shields parameter and erosion rate are also developed. Notably, the cemented soil could maintain its stability under an elevated flow of 4 m/s under an EICP treatment with 1 M of urea and calcium chloride, and a curing duration of 24 h. These findings are anticipated to serve as a valuable theoretical foundation for engineering applications.
期刊介绍:
Acta Geotechnica is an international journal devoted to the publication and dissemination of basic and applied research in geoengineering – an interdisciplinary field dealing with geomaterials such as soils and rocks. Coverage emphasizes the interplay between geomechanical models and their engineering applications. The journal presents original research papers on fundamental concepts in geomechanics and their novel applications in geoengineering based on experimental, analytical and/or numerical approaches. The main purpose of the journal is to foster understanding of the fundamental mechanisms behind the phenomena and processes in geomaterials, from kilometer-scale problems as they occur in geoscience, and down to the nano-scale, with their potential impact on geoengineering. The journal strives to report and archive progress in the field in a timely manner, presenting research papers, review articles, short notes and letters to the editors.