高岭–蒙脱混合黏土渗透各向异性的微观机理研究
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摘要
为研究高岭–蒙脱混合黏土中膨润土掺入量及固结应力对渗透各向异性比的影响,利用三轴渗透仪对高岭–蒙脱混合黏土展开一系列渗流试验,并从微观结构的改变上进行机理解读,研究发现:(1)加入膨润土后,渗透系数及渗透各向异性比明显减小,但随着膨润土掺入量的增加,渗透各向异性比趋于稳定,原因是影响渗透各向异性比的有效孔隙权重比趋于不变,导致渗透各向异性比不再发生明显改变;(2)随着有效固结应力的增大,混合黏土的渗透各向异性比不断增大。有效固结应力增大时,有效孔隙面积比和有效孔隙权重比均在增加,导致固结应力增大时渗透各向异性比增大;(3)综合膨润土掺入量及固结应力对混合黏土渗透各向异性比的影响,若从微观结构上定量分析,建议采用有效孔隙权重比作为微观参数。
A series of experiments are conducted by using the triaxial permeameters to study the influences of the incorporation ratio of bentonite and the effective consolidation stress on permeability anisotropy, and the corresponding microscopic mechanisms are investigated. The results show that:(1) When the bentonite is added, the permeability coefficient and permeability anisotropy of the mixed soil decrease significantly, but with the increasing incorporation ratio of bentonite, the permeability anisotropy tends to be stable because the effective pore proportion ratio tends to remain constant.(2) With the increasing effective consolidation stress, the permeability anisotropy of the mixed soil increases. When the effective consolidation stress increases, both the effective pore area ratio and the effective pore proportion ratio increase, which indicates that the ratio of vertical to horizontal effective pore areas is increasing.(3) Considering the influences of the incorporation ratio of bentonite and the effective consolidation stress comprehensively, if intending to quantitatively analyze the impact of these two factors from the perspective of microscopic analysis, it is recommended to use the effective pore proportion ratio as the parameter of microstructure.
A series of experiments are conducted by using the triaxial permeameters to study the influences of the incorporation ratio of bentonite and the effective consolidation stress on permeability anisotropy, and the corresponding microscopic mechanisms are investigated. The results show that:(1) When the bentonite is added, the permeability coefficient and permeability anisotropy of the mixed soil decrease significantly, but with the increasing incorporation ratio of bentonite, the permeability anisotropy tends to be stable because the effective pore proportion ratio tends to remain constant.(2) With the increasing effective consolidation stress, the permeability anisotropy of the mixed soil increases. When the effective consolidation stress increases, both the effective pore area ratio and the effective pore proportion ratio increase, which indicates that the ratio of vertical to horizontal effective pore areas is increasing.(3) Considering the influences of the incorporation ratio of bentonite and the effective consolidation stress comprehensively, if intending to quantitatively analyze the impact of these two factors from the perspective of microscopic analysis, it is recommended to use the effective pore proportion ratio as the parameter of microstructure.
引文
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[23]陈永贵,雷宏楠,贺勇,等.膨润土-红黏土混合土对NaCl溶液的渗透试验研究[J].中南大学学报(自然科学版),2018,49(4):910-915.(CHEN Yong-gui,LEI Hong-nan,HE Yong,et al.Experimental study of permeability of bentonite-laterite mixtures for salt solutions[J].Journal of Central South University(Science and Technology),2018,49(4):910-915.(in Chinese))
[24]YANG Y,APLIN A.Permeability and petrophysical propertiesof 30 natural mudstones[J].J Geophys Res,2007,112:B03206.
[25]CLEMENLTA LAPIERRE.Mercury intrusion and permeability of Louiseville clay[J].Can Geotech J,1990,27:761-773.
[26]CLENNELL M B,DEWHURST D N,BROWN K M,et al.Permeability anisotropy of consolidated clays[J].Geological Society,London,Special Publications,1999(158):79-96.
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[28]党发宁,刘海伟,王学武,等.基于有效孔隙比的黏性土渗透系数经验公式研究[J].岩石力学与工程学报,2015,34(9):1909-1917.(DANG Fa-ning,LIU Hai-wei,WANG Xue-wu,et al.Empirical formulas of permeability of clay based on effective pore ratio[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(9):1909-1917.(in Chinese))
[29]崔德山,项伟,曹李靖,等.ISS减小红色黏土结合水膜的试验研究[J].岩土工程学报,2010,32(6):944-949.(CUI De-shan,XIANG Wei,CAO Li-jing,et al.Experimental study on reducing thickness of adsorbed water layer for red clay particles treated by ionic soil stabilizer[J].Chinese Journal of Geotechnical Engineering,2010,32(6):944-949.(in Chinese))
[30]王秀艳,刘长礼.深层黏性土渗透释水规律的探讨[J].岩土工程学报,2003,25(3):308-312.(WANG Xiu-yan,LIUChang-li.Discussion on permeability of deep clayey soil[J].Chinese Journal of Geotechnical Engineering,2003,25(3):308-312.(in Chinese))
[31]冯晓腊,沈孝宇.饱和黏性土的渗透固结特性及其微观机制的研究[J].水文地质工程地质,1991(1):6-12.(FENGXiao-la,SHEN Xiao-yu.Study on the infiltration and consolidation characteristics of saturated clay and its microscopic mechanism[J].Hydrogeology and Engineering Geology,1991(1):6-12.(in Chinese))
[32]TANAKA.Poer size distribution of clayey soils measured by mercuryintrusion porosimetry and its relation to hydraulic conductivity[J].Soils and Foundations,43(6):63-73.
[2]AL-SHARRAD M A,GALLIPOLI D,WHEELER S J,et al.Experimental investigation of evolving anisotropy in unsaturated soils[J].Géotechnique,2017,67(12):1033-1049.
[3]BASAK P.Soil structure and its effects on hydraulic conductivity[J].Soil Science,1972,114(6):417-422.
[4]TAVENAS F,JEAN P,LEBLOND P,et al.The permeability of natural soft clays,Part II:Permeability characte[J].Canadian Geotechnical Journal,1983,20(4):645-660.
[5]LEROUEIL S,BOUCLIN G,TAVENAS F,et al.Permeability anisotropy of natural clays as a function of strain[J].Canadian Geotechnical Journal,1990,27(5):568-579.
[6]ADAMS A L,NORDQUIST M T J,GERMAINE J T,et al.Permeability anisotropy and resistivity anisotropy of mechanically compressed mudrocks[J].Canadian Geotechnical Journal,2016,53(9):1474-1482.
[7]KENNEY T C.Permeability ratio of repeatedly layered soils[J].Géotechnique,1963,13(4):325-333.
[8]K-J-Witt J Brauns.Permeability-anisotropydue to particle shapej[J].Geotech Engrg,1983,109:1181-1187.
[9]AL-TABBAA,WOOD D M.Some measurements of the permeability of kaolin[J].Géotechnique,1987,37:499-503.
[10]DAIGLE H,DUGAN B.Permeability anisotropy and fabric development:A mechanistic explanation[J].WaterResour Res,2011,47:W12517.
[11]柯瀚,吴小雯,张俊,等.基于优势流及各向异性随上覆压力变化的填埋体饱和渗流模型[J].岩土工程学报,2016,38(11):1957-1964.(KE Han,WU Xiao-wen,ZHANG Jun,et al.Modeling saturated permeability of municipal solid waste based on compression change of its preferential flow and anisotropy[J].Chinese Journal of Geotechnical Engineering,2016,38(11):1957-1964.(in Chinese))
[12]ZHANG D M,MA L X,ZHANG J,et al.Ground and tunnel responses induced by partial leakage in saturated clay with anisotropic permeability[J].Engineering Geology,2015,189:104-115.
[13]WONGSAROJ J,SOGA K,MAIR R J.Modelling of long-term ground response to tunnelling under St James'Park,London[J].Géotechnique,2007,57(1):75-90.
[14]王宝峰.孔隙溶液环境对黏土力学特性影响的试验研究[D].杭州:浙江大学,2017.(WANG Bao-feng.Experimental study on influence of pore solution environment on mechanical properties of clay[D].Hangzhou:Zhejiang University,2017.(in Chinese))
[15]ZAKERI A,CLUKEY E C,KEBADZE E B,et al.Fatigue analysis of offshore well conductors,Part I:Study overview and evaluation of Series 1 centrifuge tests in normally consolidated to lightly over-consolidated kaolin clay[J].Applied Ocean Research,2016,57:78-95.
[16]MESRI and Olson.Mechanisms controlling thepermeability of clays[J].Claysand ClayMinerals,1971,19:151-158.
[17]HORPIBULSUK S,YANGSUKKASEAM N,CHINKULKIJNIWAT A,et al.Compressibility and permeability of Bangkok clay compared with kaolinite and bentonite[J].Applied Clay Science,2011,52(1/2):150-159.
[18]ASTM D 5084-03 Standard test methods for measurement of hydraulic conductivity of saturated porous materials using a flexible wall permeameter[S].2003.
[19]赵铁军,姜福香.海底隧道工程耐久性技术[M].北京:人民交通出版社,2010.(ZHAO Tie-jun,JIANG Fu-xiang.Submarine tunnel engineering durability technology[M].Beijing:China Communications Press,2010.(in Chinese))
[20]李国刚.中国近海表层沉积物中黏土矿物的组成、分布及其地质意义[J].海洋学报(中文版),1990(4):470-479.(LIGuo-gang.Composition,distribution and geological significance of clay minerals in surface sediments from china offshore[J].Journal of Oceanography,1990(4):470-479.(in Chinese))
[21]吉利明,邱军利,夏燕青,等.常见黏土矿物电镜扫描微孔隙特征与甲烷吸附性[J].石油学报,2012,33(2):249-256.(JI Li-ming,QIU Jun-li,XIA Yan-qing,et al.Micro-pore characteristics and methane absorption properties of common clay minerals by electron microscope scanning[J].Acta Petrolei Sinica,2012,33(2):249-256.(in Chinese))
[22]何俊,王宇,万娟.溶液作用下黏土的界限含水率及渗透试验[J].地下空间与工程学报,2013,9(6):1277-1282.(HE Jun,WANG Yu,WAN Juan.Consistency limits and hydraulic conductivity of clay under the effect of solution[J].Chinese Journal of Underground Space and Engineering,2013,9(6):1277-1282.(in Chinese))
[23]陈永贵,雷宏楠,贺勇,等.膨润土-红黏土混合土对NaCl溶液的渗透试验研究[J].中南大学学报(自然科学版),2018,49(4):910-915.(CHEN Yong-gui,LEI Hong-nan,HE Yong,et al.Experimental study of permeability of bentonite-laterite mixtures for salt solutions[J].Journal of Central South University(Science and Technology),2018,49(4):910-915.(in Chinese))
[24]YANG Y,APLIN A.Permeability and petrophysical propertiesof 30 natural mudstones[J].J Geophys Res,2007,112:B03206.
[25]CLEMENLTA LAPIERRE.Mercury intrusion and permeability of Louiseville clay[J].Can Geotech J,1990,27:761-773.
[26]CLENNELL M B,DEWHURST D N,BROWN K M,et al.Permeability anisotropy of consolidated clays[J].Geological Society,London,Special Publications,1999(158):79-96.
[27]曹洋.波浪作用下原状软黏土动力特性与微观结构关系试验研究[D].杭州:浙江大学,2013.(CAO Yang.Experimental study on relationship between dynamic characteristics and microstructure of undisturbed soft clay under wave action[D].Hangzhou:Zhejiang University,2013.(in Chinese))
[28]党发宁,刘海伟,王学武,等.基于有效孔隙比的黏性土渗透系数经验公式研究[J].岩石力学与工程学报,2015,34(9):1909-1917.(DANG Fa-ning,LIU Hai-wei,WANG Xue-wu,et al.Empirical formulas of permeability of clay based on effective pore ratio[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(9):1909-1917.(in Chinese))
[29]崔德山,项伟,曹李靖,等.ISS减小红色黏土结合水膜的试验研究[J].岩土工程学报,2010,32(6):944-949.(CUI De-shan,XIANG Wei,CAO Li-jing,et al.Experimental study on reducing thickness of adsorbed water layer for red clay particles treated by ionic soil stabilizer[J].Chinese Journal of Geotechnical Engineering,2010,32(6):944-949.(in Chinese))
[30]王秀艳,刘长礼.深层黏性土渗透释水规律的探讨[J].岩土工程学报,2003,25(3):308-312.(WANG Xiu-yan,LIUChang-li.Discussion on permeability of deep clayey soil[J].Chinese Journal of Geotechnical Engineering,2003,25(3):308-312.(in Chinese))
[31]冯晓腊,沈孝宇.饱和黏性土的渗透固结特性及其微观机制的研究[J].水文地质工程地质,1991(1):6-12.(FENGXiao-la,SHEN Xiao-yu.Study on the infiltration and consolidation characteristics of saturated clay and its microscopic mechanism[J].Hydrogeology and Engineering Geology,1991(1):6-12.(in Chinese))
[32]TANAKA.Poer size distribution of clayey soils measured by mercuryintrusion porosimetry and its relation to hydraulic conductivity[J].Soils and Foundations,43(6):63-73.