Advances on anisotropy of the mechanical properties of compacted Gaomiaozi bentonite
YE Weimin1, 2*, ZENG Caiyun1, LU Puhuai1, LU Yu1, WANG Qiong1, CHEN Yonggui1
(1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China; 2. United Research Center for Urban Environment and Sustainable Development of the Ministry of Education, Tongji University, Shanghai 200092, China)
Abstract：The primary mineral component of bentonite is montmorillonite. The layered structure of montmorillonite causes the long axes of bentonite particles to align directionally during uniaxial static compaction into blocks, resulting in compaction-induced mechanical anisotropy. This paper systematically reviews the research progress on anisotropy in relation to swelling pressure, swelling/shrinkage deformation, compressibility, and strength characteristics, using Gaomiaozi bentonite as a case study. The findings indicate that swelling anisotropy is linked to the oriented swelling of montmorillonite crystal layers and the rearrangement of montmorillonite particles. An increase in dry density enhances the former, while higher salt concentrations suppress both mechanisms. Additionally, increased moisture content promotes structural homogenization of compacted bentonite. During loading, specimens with vertical compaction planes are more prone to particle slippage compared to those with horizontal planes, which results in reduced yield stress. Under high stress levels, initial anisotropy may diminish, while secondary anisotropy may emerge. Tensile strength is greater when tensile force is applied parallel to the crystal layer plane, and specimens with vertical compaction planes exhibit higher shear strength than those with horizontal planes. Future research should focus on the orientation of soil particles and other microstructural features, the development of predictive models for anisotropy under multi-factor coupling, in-situ testing in underground laboratories, and the behavior and evolutionary mechanisms of bentonite barriers under coupled thermos-hydro-mechanical-chemical (THMC) processes.
叶为民1，2*，曾彩云1，卢普怀1，陆 煜1，王 琼1，陈永贵1. 压实高庙子膨润土力学特性各向异性研究进展[J]. 岩石力学与工程学报, 2026, 45(6): 1842-1853.
YE Weimin1, 2*, ZENG Caiyun1, LU Puhuai1, LU Yu1, WANG Qiong1, CHEN Yonggui1. Advances on anisotropy of the mechanical properties of compacted Gaomiaozi bentonite. , 2026, 45(6): 1842-1853.
[1] 李洪辉，赵帅维，贾梅兰，等. 高放废物地质处置安全评价准则研究[J]. 核科学与工程，2016，36(3)：313–322.(LI Honghui，ZHAO Shuaiwei，JIA Meilan，et al. The study of safety assessment guide of HLW geologic disposal system[J]. Nuclear Science and Engineering，2016，36(3)：313–322.(in Chinese))
[2] 王 驹. 高放废物地质处置：进展与挑战[J]. 中国工程科学，2008，10(3)：58–65.(WANG Ju. Geological disposal of high level radio active waste: progress and challenges[J]. Strategic Study of CAE，2008，10(3)：58–65.(in Chinese))
[3] 王 驹，陈伟明，苏 锐，等. 高放废物地质处置及其若干关键科学问题[J]. 岩石力学与工程学报，2006，25(4)：801–812.(WANG Ju，CHEN Weiming，SU Rui，et al. Geological disposal of high-level radioactive waste and its key scientific issues[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(4)：801–812.(in Chinese))
[4] WEN Z J. Selection and basic properties of the buffer material for high-level radioactive waste repository in China[J]. Acta Geologica Sinica，2008，82(5)：1 050–1 055.
[5] WEN Z J. Physical property of China's buffer material for high-level radioactive waste repositories[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(4)：794–800.
[6] PUSCH R. Geological storage of highly radioactive waste[M]. Berlin：Springer-Verlag Berlin Heidelberg，2008：5–6.
[7] SATO H，SUZUKI S. Fundamental study on the effect of an orientation of clay particles on diffusion pathway in compacted bentonite[J]. Applied Clay Science，2003，23(1–4)：51–60.
[8] PUSCH R. Mineral-water interactions and their influence on the physical behavior of highly compacted Na bentonite[J]. Canadian Geotechnical Journal，1982，19(3)：381–387.
[9] JIA L Y，CHEN Y G，YE W M，et al. Effects of a simulated gap on anisotropic swelling pressure of compacted GMZ bentonite[J]. Engineering Geology，2019，248：155–163.
[10] SABA S，BARNICHON J，CUI Y J，et al. Microstructure and anisotropic swelling behaviour of compacted bentonite/sand mixture[J]. Journal of Rock Mechanics and Geotechnical Engineering，2014，6(2)：126–132.
[11] 陈永贵，雷 俊，贾灵艳，等. 圆饼状高压实膨润土膨胀力各向异性特征研究[J]. 土木工程学报，2019，52(1)：99–107.(CHEN Yonggui，LEI Jun，JIA Lingyan，et al. Anisotropic characteristics of swelling pressure for compacted GMZ pie-shaped bentonite block[J]. China Civil Engineering Journal，2019，52(1)：99–107.(in Chinese))
[12] 陈正汉. 缓冲/回填材料的热–水–力耦合特性及其应用[M]. 北京：科学出版社，2017：105–131.(CHEN Zhenghan. Thermo-hydro-mechanical coupling properties and applications of buffer/backfill materials[M]. Beijing：Science Press，2017：105–131.(in Chinese))
[13] LU Y，YE W M，WANG Q，et al. Insights into anisotropic swelling pressure of compacted GMZ bentonite[J]. Acta Geotechnica，2023，18(11)：5 721–5 734.
[14] 汪 龙，方祥位，申春妮，等. 膨润土–砂混合材料三向膨胀力试验研究[J]. 地下空间与工程学报，2015，11(4)：940–945.(WANG Long，FANG Xiangwei，SHEN Chunni，et al. Three-dimensional swelling pressure characteristic of bentonite-sand mixtures[J]. Chinese Journal of Underground Space and Engineering，2015，11(4)：940–945.(in Chinese))
[15] MA J，CHEN Y G，JIA L Y，et al. Anisotropic swelling pressures of compacted GMZ bentonite infiltrated with salt solutions[J]. Journal of Rock Mechanics and Geotechnical Engineering，2024，16(9)：3 772–3 785.
[16] 雷 俊. 压实GMZ膨润土膨胀力各向异性特征[硕士学位论文][D]. 上海：同济大学，2018.(LEI Jun. Anisotropy characteristics of swelling pressure of compacted GMZ bentonite[M. S. Thesis][D]. Shanghai：Tongji University，2018.(in Chinese))
[17] MARTIN P L，BARCALA J M，HUERTAS F，et al. Large-scale and long-term coupled thermo-hydro-mechanic experiments with bentonite: the FEBEX mock-up test[J]. Journal of Iberian Geology，2006，32(2)：259–282.
[18] WANG Q，TANG A M，CUI Y J，et al. The effects of technological voids on the hydro-mechanical behaviour of compacted bentonite-sand mixture[J]. Soils and Foundations，2013，53(2)：232–245.
[19] LI X L，BASTIAENS W，VAN M P，et al. Design and development of large-scale in-situ PRACLAY heater test and horizontal high-level radioactive waste disposal gallery seal test in Belgian HADES[J]. Journal of Rock Mechanics and Geotechnical Engineering，2010，2(2)：103–110.
[20] YE W M，CHEN Y G，CHEN B，et al. Advances on the knowledge of the buffer/backfill properties of heavily-compacted GMZ bentonite[J]. Engineering Geology，2010，116：12–20.
[21] 张虎元，王学文，刘 平，等. 缓冲回填材料砌块接缝密封及愈合研究[J]. 岩石力学与工程学报，2016，35(增2)：3 605–3 614. (ZHANG Huyuan，WANG Xuewen，LIU Ping，et al. Sealing and healing of compacted bentonite block joints in HLW disposal[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(Supp.2)：3 605–3 614.(in Chinese))
[22] SEIPHOORI A，FERRARI A，LALOUI L. Water retention behaviour and microstructural evolution of MX-80 bentonite during wetting and drying cycles[J]. Géotechnique，2014，64(9)：721–734.
[23] WEMAERE I，MARIVOET J，LABAT S. Hydraulic conductivity variability of the Boom Clay in north-east Belgium based on four core drilled boreholes[J]. Physics and Chemistry of the Earth，2008，33：S24–S36.
[24] ALONSO E E，ROMERO E，HOFFMANN C，et al. Expansive bentonite-sand mixtures in cyclic controlled-suction drying and wetting[J]. Engineering Geology，2005，81(3)：213–226.
[25] 柴肇云，张 鹏，郭俊庆，等. 泥质岩膨胀各向异性与循环胀缩特征[J]. 岩土力学，2014，35(2)：346–350.(CHAI Zhaoyun，ZHANG Peng，GUO Junqing，et al. Swelling anisotropy and cyclic swelling-shrinkage of argillaceous rock[J]. Rock and Soil Mechanics，2014，35(2)：346–350.(in Chinese))
[26] LU Y，YE W M，WANG Q，et al. Anisotropic swelling behaviour of unsaturated compacted GMZ bentonite hydrated under vertical stresses[J]. Bulletin of Engineering Geology and the Environment，2021，80(7)：5 515–5 526.
[27] 陆 煜.非饱和高压实膨润土体变与强度各向异性特征及其本构模型[博士学位论文][D]. 上海：同济大学，2020.(LU Yu. Anisotropic volume change/strength property and its constitutive model for unsaturated highly compacted bentonite[Ph. D. Thesis][D]. Shanghai：Tongji University，2020.(in Chinese))
[28] TAN Y，ZHANG H Y，ZHANG T W，et al. Anisotropic hydro-mechanical behavior of full-scale compacted bentonite-sand blocks[J]. Engineering Geology，2021，287：106093.
[29] ZHU Y H，YE W M，WANG Q，et al. Anisotropic volume change behaviour of uniaxial compacted GMZ bentonite under free swelling condition[J]. Engineering Geology，2020，278：105821.
[30] 朱远鸿. 压实高庙子膨润土各向异性变形特征试验研究[硕士学位论文][D]. 上海：同济大学，2019.(ZHU Yuanhong. Experiment study on the anisotropic deformation behavior of uniaxial compacted GMZ bentonite[M. S. Thesis][D]. Shanghai：Tongji University，2019.(in Chinese))
[31] HOFFMANN C，ALONSO E E，ROMERO E. Hydro-mechanical behaviour of bentonite pellet mixtures[J]. Physics and Chemistry of the Earth，2007，32：832–849.
[32] LLORET A，VILLAR M V. Advances on the knowledge of the thermo-hydro-mechanical behaviour of heavily compacted “FEBEX” bentonite[J]. Physics and Chemistry of the Earth，2007，32：701–715.
[33] POWELL J S，TAKE W A，SIEMENS G，et al. Time-dependent behaviour of the bearpaw shale in oedometric loading and unloading[J]. Canadian Geotechnical Journal，2012，49(4)：427–441.
[34] LU Y，YE W M，WANG Q，et al. Insights into anisotropic compression characteristics of unsaturated compacted GMZ bentonite[J]. Bulletin of Engineering Geology and the Environment，2024，83：459.
[35] 秦臻宇，孙德安，周祥运，等. 压实高庙子膨润土抗拉强度各向异性[J]. 上海大学学报：自然科学版，2022，28(4)：668–677.(QIN Zhenyu，SUN Dean，ZHOU Xiangyun，et al. Anisotropy of tensile strength of compacted Gaomiaozi bentonite[J]. Journal of Shanghai University：Natural Science，2022，28(4)：668–677.(in Chinese))
[36] LU Y，YE W M，WANG Q，et al. Shear strength characteristics of unsaturated compacted GMZ bentonite considering anisotropy[J]. Engineering Geology，2024，342：107743.
[37] 赵乃峰. 基于双孔结构特征的压实膨润土弹塑性水–力耦合本构模型[博士学位论文][D]. 上海：同济大学，2018.(ZHAO Naifeng. An elastoplastic hydro-mechanical coupled constitutive model for compacted bentonite with double structure approach[Ph. D. Thesis][D]. Shanghai：Tongji University，2018.(in Chinese))
[38] ALONSO E E，GENS A，HIGHT D W. Special problem soils: general report[C]// Proceedings of the Ninth European Conference on Soil Mechanics and Foundation Engineering. Rotterdam：A. A. Balkema，1989：1 087–1 146.
[39] ROSCOE K H，BURLAND J B. On the generalized stress-strain behaviour of wet clay[C]// HEYMAN J，LECKIE F A，ed. Engineering Plasticity：Papers for a Conference held in Cambridge，March 1968. London：Cambridge University Press，1968：535–608.
[40] ALONSO E E，GENS A. JOSA A. A constitutive model for partially saturated soils[J]. Géotechnique，1990，40(3)：405–430.
[41] WHEELER S J. Inclusion of specific water volume within an elasto-plastic model for unsaturated soil[J]. Canadian Geotechnical Journal，1996，33(1)：42–57.
[42] GENS A，ALONSO E E. A framework for the behaviour of unsaturated expansive clays[J]. Canadian Geotechnical Journal，1992，29(6)： 1 013–1 032.
[43] ALONSO E E，VAUNAT J，GENS A. Modelling the mechanical behaviour of expansive clays[J]. Engineering Geology，1999，54： 173–183.
[44] CUI Y J，DELAGE P. Yielding and plastic behaviour of an unsaturated compacted silt[J]. Géotechnique，1996，46(2)：291–311.
[45] WHEELER S J，NÄÄTÄNEN A，KARSTUNEN M，et al. An anisotropic elastoplastic model for soft clays[J]. Canadian Geotechnical Journal，2003，40(2)：403–418.
2026, Vol. 45 
