水利水电技术（中英文）2024，Vol.55Issue(7)：134-146,13.DOI:10.13928/j.cnki.wrahe.2024.07.012
生物炭联合微生物矿化技术改善软土力学性能试验研究
Enhancement of shear strength of soft soil using MICP combined with biochar
摘要
Abstract
[Objective]Reinforcing the soft soil foundations in an environmentally friendly way holds significant importance on engineering construction and ecological environment.Therefore,the microbially induced carbonate precipitation(MICP)com-bined with bio-char method was introduced to the soft soil.[Methods]The optimal concentration of bacterial solution and cemen-tation solution of MICP-treated soft soil were determined using direct shear test.The effect of bio-char mixing ratio and curing time on the shear strength of MICP-bio-char-treated soft soil were investigated.The scanning electron microscope(SEM),X-ray diffraction(XRD)and Energy Dispersive Spectrometer(EDS)test were employed to reveal the microstructures,mineral compo-sition and distribution characteristics of elements.[Results]The results showed that the optimal parameters for improving the strength of MICP-treated soft soil was 0.9 of OD600 and 1.0 mol/L of cementation solution concentration,on the 28th day.In this case,the maximum values of internal friction angel and cohesion were 11.3 degrees and 12.15 kPa,respectively.Furthermore,the cohesion and internal friction angle greatly increased with the increase of bio-char mixing ratio and curing time.The optimal values of internal friction angle and cohesion were obtained when the bio-char mixing ratio was 12％and curing time was 28 days,which were 20.8 degrees and 16.61 kPa,respectively.During 28 days of curing time,the growth rates were higher within 14 days than those of later 14 days.Additionally,a large amount of calcium carbonate was observed in the MICP-treated soft soil.The calcium carbonate precipitated on the interface between bio-char and soft soil was the source of strength improvement com-pared with bio-char treated soft soil.Analysis of EDS indicated that there was a significant distribution of calcium,carbon,and oxygen elements on the surface of the soil sample.[Conclusion]It was demonstrated that the feasibility of bio-char combined with MICP on solidifying the soft soil.Furthermore,the findings of this study provide a new perspective for environmentally friendly reinforcement of soft soil in coastal areas.关键词
微生物诱导碳酸钙沉淀/软土/生物炭/内摩擦角/黏聚力/力学性能Key words
microbially induced carbonate precipitation(MICP)/soft soil/biochar/internal friction angle/cohesion/mechani-cal property分类
建筑与水利引用本文复制引用
崔秀丽,李佳禧,谢佳旻,林军,庞书孟..生物炭联合微生物矿化技术改善软土力学性能试验研究[J].水利水电技术（中英文）,2024,55(7):134-146,13.基金项目
广东省自然科学基金(2021A1515110677) （2021A1515110677）
广东省普通高校青年创新人才类项目(2022KQNCX237) （2022KQNCX237）
汕头职业技术学院科研课题项目(SZK2023Z01) （SZK2023Z01）
国家重点研发计划(2022YFC3202900) （2022YFC3202900）
