Microscopic interpretation of time-dependent strength of clay considering plate-like particle interactions
-
摘要: 为了探寻黏土强度时效性的微观机理,将时效强度与板状黏土颗粒搭接方式和相互作用势能联系起来,颗粒间的相互作用力使颗粒朝着势能较低的位置搭接,当颗粒间相互作用势能最低时,时效强度达到稳定值。提出了可考虑两板状颗粒间夹角θ和距离d影响的颗粒相互作用总势能公式,可用Zeta电位代替表面电位来计算势能,计算结果与实际情况相吻合。通过计算可知：①黏土时效强度与电解质浓度有很大关系,电解质浓度较低时（≤10-3 mol/L）,两颗粒相互垂直时的总势能最低；电解质浓度较高时（≥10-1 mol/L）,两颗粒相互平行时的总势能最低,时效强度几乎不变,甚至会减小；中间电解质浓度是过渡状态；②两黏土颗粒的稳定搭接方式主要是垂直和平行,两颗粒之间总会趋于向稳定搭接方式转化,这也是时效强度经历一定时间而达到稳定值的过程；③解释了黏土触变强度恢复的原因,即颗粒会一直趋于搭接强度最高的垂直稳定搭接。Abstract: In order to explore its micro-mechanism, the time-dependent strength of clay is related to the overlapping mode and interaction potential of plate-like clay particles. The interaction force between the particles causes the particles to overlap toward a position with a lower potential energy. When the potential energy between the particles is the lowest, the time-dependent strength reaches a stable value. A total potential energy formula is proposed to consider the interaction between two adjacent plate-like particles with certain angle θ and distance d, where the Zeta potential can be used instead of surface potential to calculate the potential energy. The calculated results of the total potential energy are consistent with the actual situations. It is shown: (1) The time-dependent strength of clay has a close relationship with the electrolyte content. When the electrolyte concentration is low (≤10-3 mol/L), the total potential energy is the lowest while the two adjacent particles are perpendicular. When the electrolyte concentration is high (≥10-1 mol/L), the total potential energy is the lowest while the two adjacent particles are parallel, and the time-dependent strength is almost unchanged, or even reduced. (2) The stable overlap of clay particles is mainly vertical and parallel. The two adjacent particles will always tend to be overlapped each other in one of these two ways, and so it takes some time for clay to reach a stable value of the time-dependent strength. (3) The reason for the restoration of thixotropic strength of general clay may be explained as that particles will always tend to overlap vertically, and this overlap way leads to the highest strength of clay.
-
-
![]()
图 2 计算板状颗粒相互作用势能示意图
Figure 2. Schematic diagram of calculating potential energy between plate-like particles
![]()
图 5 小距离低浓度电解质条件下的颗粒静电势能分布
Figure 5. Distribution of electrostatic potential energy of particles with short distance and low concentration electrolyte
![]()
图 6 大距离低浓度电解质条件下的颗粒静电势能分布
Figure 6. Distribution of electrostatic potential energy of particles with large distance and low concentration electrolyte
![]()
图 7 高浓度电解质条件下的颗粒静电势能
Figure 7. Electrostatic potential energies of particles with high concentration electrolyte
![]()
图 8 不同电解质浓度条件下的颗粒静电零势能位置
Figure 8. Positions of zero potential energy of static electricity with different electrolyte contents
![]()
图 13 低浓度电解质条件下的颗粒势能分布
Figure 13. Distribution of potential energy of particles with low concentration electrolyte
![]()
图 14 高浓度电解质条件下的颗粒势能分布
Figure 14. Distribution of potential energy of particle with high concentration electrolyte
![]()
图 15 不同电解质浓度条件下的颗粒最低势能分布
Figure 15. Distribution of lowest potential energy of particles under different electrolyte concentrations
![]()
图 16 小距离高电解质浓度条件下的颗粒最低势能分布
Figure 16. Distribution of lowest potential energy of particles under high electrolyte concentration and small distance
![]()
图 17 由表面电位得到的最低势能分布
Figure 17. Distribution of lowest potential energy derived from surface potential
表 1 一价阳离子浓度与κ的关系
Table 1 Relationship between monovalent cation concentration and κ
浓度/(mol·L-1) 10-5 10-4 10-3 10-2 10-1 κ/(m-1) 107 3.3×107 108 3.3×108 109 
下载: 导出CSV
表 2 不同厚度c颗粒的表面平均间距范围
Table 2 Ranges of average surface spacing of particles with different c
(nm) c 0.96 3.33 5.70 8.07 下限 7 10 10 10 上限 25 48 72 95
下载: 导出CSV
表 3 Zeta电位与表面电位的量值
Table 3 Values of Zeta potential and surface potential
电位 电解质浓度/(mol·L-1) 10-5 10-4 10-3 10-2 10-1 表面电位 -330.4 -271.9 -213.8 -157.1 -103.8 γ2 0.9947 0.9829 0.9462 0.8418 0.6047 Zeta电位 -46.2 -45.2 -41.5 -37.2 -28.4 γ2 0.1868 0.1798 0.1546 0.1268 0.0767 γ2 增大倍数5.32 5.47 6.12 6.64 7.88
下载: 导出CSV
-
[1] 张先伟, 孔令伟, 李峻, 等. 黏土触变过程中强度恢复的微观机理[J]. 岩土工程学报, 2014, 36(8): 1407-1413. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201408006.htm ZHANG Xian-wei, KONG Ling-wei, LI Jun, et al. Microscopic mechanism of strength increase of clay during thixotropic process[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(8): 1407-1413. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201408006.htm
[2] ZHANG X W, KONG L W, YANG A W. et al. Thixotropic mechanism of clay: a microstructural investigation[J]. Soils and Foundations, 2017, 57(1): 23-35. doi: 10.1016/j.sandf.2017.01.002
[3] 霍海峰, 齐麟, 雷华阳, 等. 天津软黏土触变性的思考与试验研究[J]. 岩石力学与工程学报, 2016, 35(3): 631-637. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201603020.htm HUO Hai-feng, QI Lin, LEI Hua-yang, et al. Analysis and experimental study on thixotropy of Tianjin soft clay[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(3): 631-637. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201603020.htm
[4] OGDEN F L, RUFF J F. Setting time effects on bentonite water-well annulus seals[J]. Journal of Irrigation and Drainage Engineering, 1991, 117(4): 534-545. doi: 10.1061/(ASCE)0733-9437(1991)117:4(534)
[5] OGDEN F L, RUFF J F. Strength of bentonite water-well annulus seals in confined aquifers[J]. Journal of Irrigation and Drainage Engineering, 1993, 199(2): 242-250.
[6] OSIPOV V I, NIKOLAEVA S K, SOKOLOV V N. Microstructural changes associated with thixotropic phenomena in clay soils[J]. Géotechnique, 1984, 34(3): 293-303. doi: 10.1680/geot.1984.34.3.293
[7] DERJAGUIN B V, LANDAU L. Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solutions of electrolytes[J]. Acta Physicochim, URSS, 1941, 14: 633-662.
[8] VERWEY E J W, OVERBEEK J T G. Theory of the Stability of Lyophobic Colloids[M]. Amsterdam: Elsevier Publishing Company, Inc, 1948.
[9] PETER B L, JOHN C B. Relating clay yield stress to colloidal parameters[J]. Journal of Colloid and Interface Science, 2006. 296: 749-755. doi: 10.1016/j.jcis.2005.09.061
[10] SAKAIRI N, KOBAYASHI M, ADACHI Y. Effects of salt concentration on the yield stress of sodium montmorillonite suspension[J]. Journal of Colloid and Interface Science, 2005, 283: 245-250. doi: 10.1016/j.jcis.2004.08.181
[11] MISSANA1 T, ADELL A. On the applicability of DLVO theory to the prediction of clay colloids stability[J]. Journal of Colloid and Interface Science, 2000, 230: 150-156. doi: 10.1006/jcis.2000.7003
[12] 苗司晗. 2∶1型黏土团聚体稳定性及黏土水迁移中的离子特异性效应[D]. 重庆: 西南大学, 2017. MIAO Si-han. 2:1 Type Clay Aggregate Stability and Ion Specific Effect in Clay Water Migration[D]. Chongqing: Southwest University, 2017. (in Chinese)
[13] 陈宝, 田昌春, 郭家兴, 等. 地下水对压实高庙子膨润土冲蚀作用研究[J]. 岩土力学, 2016, 37(11): 3224-3230. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201611023.htm CHEN Bao, TIAN Chang-chun, GUO Jia-xing, et al. Erosion of compacted Gaomiaozi bentonite by groundwater flow[J]. Rock and Soil Mechanics, 2016, 37(11): 3224-3230. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201611023.htm
[14] 陈宝, 田昌春, 郭家兴, 等. 高庙子膨润土悬浮液的抗冲蚀流变特性[J]. 同济大学学报(自然科学版), 2017, 45(3): 317-322. https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ201703003.htm CHEN Bao, TIAN Chang-chun, GUO Jia-xing, et al. Anti-erosion Rheological Characteristics of Gaomiaozi Bentonite Suspension[J]. Journal of Tongji University (Natural Science), 2017, 45(3): 317-322. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ201703003.htm
[15] SENG S, TANAKA H. Properties of very soft clays: a study of thixotropic hardening and behavior under low consolidation pressure[J]. Soils and Foundations, 2012, 52(2): 335-345. doi: 10.1016/j.sandf.2012.02.010
[16] VAN OLPHEN H. An Introduction to Clay Colloid Chemistry[M]. 2nd ed. New York: John Wiley & Sons, 1977.
[17] RUSSEL W B, SAVILLE D A. Colloidal Dispersions[M]. Cambridge: Cambridge University Press, 1991.
[18] HIEMENZ P C, RAJAGOPALAN R. Principles of Colloid and Surface Chemistry, Revised and Expanded[M]. Boca Raton: CRC Press, 2016.
[19] NGUYEN A, SCHULZE H J. Colloidal Science of Flotation[M]. Boca Raton: CRC Press, 2003.
[20] OTSUKI A. Coupling colloidal forces with yield stress of charged inorganic particle suspension: a review[J]. Electrophoresis, 2018, 39(5/6): 690-701.
[21] 郭霞, 傅强, 田锐, 等. 动态光散射技术测定土壤／黏土胶体的Hamaker常数[J]. 西南大学学报(自然科学版), 2016, 38(6): 74-81. https://www.cnki.com.cn/Article/CJFDTOTAL-XNND201606016.htm GUO Xia, FU Qiang, TIAN Rui, et al. Dynamic light scattering technology determination the hamaker constant of soil/clay colloids[J]. Journal of Southwest University (Natural Science Edition), 2016, 38(6): 74-81. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XNND201606016.htm
[22] 刘成伦, 徐龙君, 鲜学福. 水溶液中盐的浓度与其电导率的关系研究[J]. 中国环境监测, 1999(4): 21-24. https://www.cnki.com.cn/Article/CJFDTOTAL-IAOB199904008.htm LIU Cheng-lun, XU Long-jun, XIAN Xue-fu. Study on the relationship between concentration of salt solution and its conductivity[J]. Environmental Monitoring in China, 1999(4): 21-24. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-IAOB199904008.htm
[23] ELIMELECH M, GREGORY J, JIA X. Particle Deposition and Aggregation: Measurement, Modelling and Simulation[M]. Oxford: Butterworth-Heinemann, 2013.
[24] 陈永贵, 蒯琪, 叶为民, 等. 高压实膨润土膨胀力预测研究[J]. 同济大学学报(自然科学版), 2018, 46(12): 1628-1636. https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ201812003.htm CHEN Yong-gui, KUAI Qi, YE Wei-Min, et al. Prediction of swelling pressure for compacted bentonite[J]. Journal of Tongji University (Natural Science), 2018, 46(12): 1628-1636. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ201812003.htm
[25] 商翔宇, 鲁巨明, 杨晨, 等. 考虑黏土特性的离散元程序开发[J]. 防灾减灾工程学报, 2016, 36(4): 657-663. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXK201604023.htm SHANG Xiang-yu, LU Ju-ming, YANG Chen, et al. Development of discrete element code considering the characteristics of clay[J]. Journal of Disaster Prevention and Mitigation Engineering, 2016, 36(04): 657-663. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-DZXK201604023.htm
[26] 周青. 蒙脱石层间域微结构及其吸附有机物的分子模拟[D]. 广州: 中国科学院研究生院(广州地球化学研究所), 2015. ZHOU Qing. Molecular Simulations of the Montmorillonite Interlayer microstructure and the Sorption towards Organics[D]. Guangzhou: Chinese Academy of Sciences (Guangzhou Institute of Geochemistry), 2015. (in Chinese)
[27] 周金虹. 黏土矿物孔道表面与流体相互作用的分子模拟[D]. 南京: 南京大学, 2019. ZHOU Jin-hong. Molecular Simulation of Interaction Between Clay Mineral Pore Surface and Fluid[D]. Nanjing: Nanjing University, 2019. (in Chinese)
[28] HOU J, LI H, ZHU H, et al. Determination of clay surface potential: a more reliable approach[J]. Soil Science Society of America Journal, 2009, 73(5): 1658-1663.
[29] HU F, XU C, LI H, et al. Particles interaction forces and their effects on soil aggregates breakdown[J]. Soil and Tillage Research, 2015, 147: 1-9.
计量
- 文章访问数:
- HTML全文浏览量: 0
- PDF下载量:
