微生物诱导碳酸钙沉淀(MICP)作为一种新型微生物加固技术,能够改变裂隙岩体水力性能,具有阻渗作用。采用巴氏芽孢杆菌对劈裂法预制的贯通裂隙红砂岩试样进行微生物充填试验,并分析试样渗透性能改变情况,同时通过电化学阻抗谱法(EIS)分析微生物充填对裂隙岩体结构的影响,对微生物充填裂隙岩体的阻渗机理作综合研究。研究结果表明:①微生物充填可使裂隙岩体渗透系数降低1~2个数量级,充填率越高充填效果越好;②裂隙宽度和围压对微生物充填后渗透系数改变具有一定的影响;③裂隙岩体充填前后渗透系数随围压的增大呈幂函数降低;④EIS测量结果表明,微生物充填后,裂隙岩体导电性能提高,岩体密实,渗透性能降低。
Abstract
As a novel microbial reinforcement technology, microbially induced calcium carbonate precipitation (MICP) could change the hydraulic performance of fractured rock mass and barrier penetrations. Bacillus pasteurii was used as microbial filler to test the permeability performance of red sandstone specimens with penetrated fracture prepared by splitting. Furthermore, electrochemical impedance spectroscopy (EIS) method was employed to examine the influence of microbial filling on the structure of fractured rock mass, and further probe into the impermeability mechanism. Research results unveiled that 1) the permeability of fractured red sandstone can be reduced by 1-2 orders of magnitude by MICP; higher filling rate will result in better effect. 2) Crack width and confining pressure have impact on the change of permeability coefficient of fractured rock after microbial filling. 3) The permeability coefficient of fractured rock before and after microbial filling declines in a power relation with the growth of confining pressure. 4) The fractured sandstone after microbial filling is more conductive and denser than that before microbial filling, which explains the reduction of permeability coefficient.
关键词
裂隙岩体 /
阻渗机理 /
微生物诱导碳酸钙沉淀 /
电化学阻抗谱法 /
水力性能
Key words
fractured rock mass /
impermeability mechanism /
MICP /
EIS /
hydraulic performance
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参考文献
[1] 李术才,宋曙光,李利平,等.海底隧道流固耦合模型试验系统的研制及应用[J].岩石力学与工程学报,2013,32(5):883-890.
[2] 葛家良.化学灌浆技术的发展与展望[J].岩石力学与工程学报,2006,25(增刊 2):3384-3392.
[3] 陈愈炯.压密和劈裂灌浆加固地基的原理和方法[J].岩土工程学报,1994,16(2):22-28.
[4] LIU D, SHAO A L, JIN C Y, et al. Healing Technique for Rock Cracks Based on Microbiologically Induced Calcium Carbonate Mineralization[J]. Journal of Materials in Civil Engineering, 2018, 30(11): 82-86.
[5] DEJONG J T, SOGA K, KAVAZANJIAN E, et al. Biogeochemical Processes and Geotechnical Applications: Progress, Opportunities and Challenges[J]. Géotechnique, 2013, 63(4): 287-301.
[6] TOBLER D J, MINTO J, EL MOUNTASSIR G, et al. Microscale Analysis of Fractured Rock Sealed With Microbially Induced CaCO3 Precipitation: Influence on Hydraulic and Mechanical Performance[J]. Water Resources Research, 2018, 54(10): 8295-8308.
[7] WU C Z, CHU J, WU S F, et al. 3D Characterization of Microbially Induced Carbonate Precipitation in Rock Fracture and the Resulted Permeability Reduction[J]. Engineering Geology, 2019, 249: 23-30.
[8] KIM S, TENTZERIS M M, JIN G, et al. Factors Affecting Efficiency of Microbially Induced Calcite Precipitation[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2012, 138(8): 992-1001.
[9] MINTO J, MACLACHLAN E, EL MOUNTASSIR G, et al. Rock Fracture Grouting with Microbially Induced Carbonate Precipitation[J]. Water Resources Research, 2016, 52(1): 8827-8844.
[10]HOMMEL J, LAUCHNOR E, PHILLIPS A, et al. A Revised Model for Microbially Induced Calcite Precipitation: Improvements and New Insights Based on Recent Experiments[J]. Water Resources Research, 2015, 51(5):3695-3715.
[11]PHILLIPS A J, CUNNINGHAM A B, GERLACH R, et al. Fracture Sealing with Microbially-induced Calcium Carbonate Precipitation: A Field Study[J]. Environmental Science & Technology, 2016, 50(7): 4111-4117.
[12]CUTHBERT M, MCMILLAN L A, HANDLEY-SIDHU S, et al. A Field and Modeling Study of Fractured Rock Permeability Reduction Using Microbially Induced Calcite Precipitation[J]. Environmental Science & Technology, 2013, 47(23): 13637-13643.
[13]张 铭.低渗透岩石实验理论及装置[J].岩石力学与工程学报,2003,22(6):919-925.
[14]MA D, MIAO X X, CHEN Z Q, et al. Experimental Investigation of Seepage Properties of Fractured Rocks under Different Confining Pressures[J]. Rock Mechanics and Rock Engineering, 2013, 46(5): 1135-1144.
[15]贺玉龙,陶玉敬,杨立中.不同节理粗糙度系数单裂隙渗流特性试验研究[J].岩石力学与工程学报,2010,29(增刊1):3235-3240.
[16]YANG J, ZHANG Q G, YANG Y M, et al. An Experimental Investigation on the Mechanism of Fluid Flow Through Single Rough Fracture of Rock[J]. Science China Technological Sciences, 2013, 56(8): 2070-2080.
[17]NOVER G, HEIKAMP S, FREUND D. Electrical Impedance Spectroscopy Used as a Tool for the Detection of Fractures in Rock Samples Exposed to either Hydrostatic or Triaxial Pressure Conditions[J]. Natural Hazards, 2000, 21: 317-330.
[18]HAN P J, ZHANG Y F, CHEN F Y, et al. Interpretation of Electrochemical Impedance Spectroscopy (EIS) Circuit Model for Soils[J]. Journal of Central South University, 2015, 22: 4318-4328.
[19]SUN H F, REN Z L, ALI MEMON S, et al. Investigating Drying Behavior of Cement Mortar Through Electrochemical Impedance Spectroscopy Analysis[J]. Construction and Building Materials, 2017, 135: 361-368.
基金
国家自然科学基金项目(51508579,51674287)
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