留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

掺砂率与干密度对膨润土收缩特性影响

马鸿发 刘清秉 李靖

马鸿发, 刘清秉, 李靖. 掺砂率与干密度对膨润土收缩特性影响[J]. 地质科技通报, 2023, 42(6): 76-85. doi: 10.19509/j.cnki.dzkq.tb20220099
引用本文: 马鸿发, 刘清秉, 李靖. 掺砂率与干密度对膨润土收缩特性影响[J]. 地质科技通报, 2023, 42(6): 76-85. doi: 10.19509/j.cnki.dzkq.tb20220099
Ma Hongfa, Liu Qingbing, Li Jing. Effect of shrinkage characteristics of bentonite with different sand mixing rates and dry densities[J]. Bulletin of Geological Science and Technology, 2023, 42(6): 76-85. doi: 10.19509/j.cnki.dzkq.tb20220099
Citation: Ma Hongfa, Liu Qingbing, Li Jing. Effect of shrinkage characteristics of bentonite with different sand mixing rates and dry densities[J]. Bulletin of Geological Science and Technology, 2023, 42(6): 76-85. doi: 10.19509/j.cnki.dzkq.tb20220099

掺砂率与干密度对膨润土收缩特性影响

doi: 10.19509/j.cnki.dzkq.tb20220099
基金项目: 

国家自然科学基金项目 41972298

详细信息
    作者简介:

    马鸿发(1998—), 男, 现正攻读地质工程专业硕士学位, 主要从事膨润土工程性质方面的研究工作。E-mail: wuther12@qq.com

    通讯作者:

    刘清秉(1984—), 男, 副研究员, 主要从事特殊土工程性质方面的研究工作。E-mail: liuqingbing_1357@163.com

  • 中图分类号: TU443

Effect of shrinkage characteristics of bentonite with different sand mixing rates and dry densities

  • 摘要:

    膨润土具有明显胀缩性, 收缩引起膨润土的强度变化并伴随着裂隙的产生, 对工程结构安全有非常重要的影响, 研究膨润土的收缩性对工程安全具有重要意义。通过对膨润土开展恒温干燥收缩试验, 结合数字图像技术, 从干密度和掺砂率2个方面研究其对土体干燥收缩过程中水分蒸发、各向收缩应变和裂隙的影响。土体的干燥收缩过程可以分为减速阶段和残余阶段, 高干密度和高掺砂率土样在干燥收缩过程中失水更少、各向收缩应变更小、裂隙更少。通过扫描电镜试验观察得到高干密度和高掺砂率的土体在微观结构上更加均匀、密实, 孔隙明显减少。针对土样收缩特征模型的选取发现T&D模型数据拟合效果较好。试验表明提高掺砂率和干密度是减小膨润土收缩性的有效手段。

     

  • 图 1  试验装置示意图

    Figure 1.  Schematic diagram of the test device

    图 2  不同掺砂率土样含水率曲线(a)和蒸发速率曲线(b)

    1.5-T.初始干密度为1.5 g/cm3,未掺砂土样;1.5-10T.初始干密度为1.5 g/cm3,掺砂率为10%土样;1.5-20T.初始干密度为1.5 g/cm3,掺砂率为20%土样;1.5-30T.初始干密度为1.5 g/cm3,掺砂率为30%土样;1.5-50T.初始干密度为1.5 g/cm3,掺砂率为50%土样,下同

    Figure 2.  Moisture content curve (a) and evaporation rate curve (b) for soil samples with different sand content ratios

    图 3  不同初始干密度土样含水率曲线(a)和蒸发速率曲线(b)

    Figure 3.  Moisture content curve (a) and evaporation rate curve (b) for soil samples with different dry densities

    图 4  不同掺砂率土样的轴向收缩应变曲线(a)和径向收缩应变曲线(b)

    Figure 4.  Axial strain curves (a) and radial strain curves (b) for soil samples with different sand content ratios

    图 5  不同掺砂率土样校正前(a)、后(b)体积收缩应变曲线

    Figure 5.  Volume strain curves for soil samples with different sand content ratios before (a) and after (b) calibration

    图 6  不同掺砂率土样收缩应变特征参数

    Figure 6.  Shrinkage characteristic parameters for soil samples with different sand content ratios

    图 7  不同初始干密度下土样体积收缩应变参数

    Figure 7.  Volume shrinkage strain parameters for soil samples with different dry densities

    图 8  土样最终裂隙发育状态

    a1, a2, a3, a4.掺砂率0,干密度分别为1.2, 1.3, 1.4, 1.5 g/cm3;b1, b2, b3, b4.掺砂率10%,干密度分别为1.2, 1.3, 1.4, 1.5 g/cm3;c1, c2, c3, c4.掺砂率20%,干密度分别为1.2, 1.3, 1.4, 1.5 g/cm3;d1, d2, d3, d4.掺砂率30%,干密度分别为1.2, 1.3, 1.4, 1.5 g/cm3

    Figure 8.  Final fissure development status of soil samples

    图 9  不同掺砂率土样表面裂隙率曲线

    Figure 9.  Surface fissure rate curves for soil samples with different sand content ratios

    图 10  不同初始干密度土样裂隙参数图

    Figure 10.  Fissure parameters for soil samples with different dry densities

    图 11  初始干密度1.5 g/cm3试样模型拟合曲线

    Figure 11.  Fitting curves of model for soil sample with dry density of 1.5 g/cm3

    图 12  不同掺砂率微观结构图片

    Figure 12.  Microstructure pictures for soil sample with different sand content rates

    图 13  不同初始干密度微观结构图片

    Figure 13.  Microstructure pictures for soil sample with different dry densities

    表  1  膨润土主要化学成分

    Table  1.   Main chemical components of bentonite

    成分 SiO2 Al2O3 Fe2O3 MgO CaO Na2O K2O MnO TiO2 P2O5
    wB/% 61.52 16.62 4.73 5.45 2.73 0.13 0.11 0.03 0.30 0.03
    下载: 导出CSV

    表  2  膨润土基本物理性质

    Table  2.   Basic physical properties of bentonite

    密度/(g·cm-3) 液限/% 塑限/% 比表面积/(m2·g-1) 自由膨胀率/% 线缩率/% 缩限/% 体缩率/%
    2.75 155.08 49.54 468.2 155.0 2.22 24.0 27.0
    下载: 导出CSV

    表  3  干密度1.5 g/cm3模型拟合参数

    Table  3.   Fitting parameters for soil sample with dry density of 1.5 g/cm3

    掺砂率/% k0 k1 k2 k3 相关系数R2
    0 0.710 95 -0.766 96 2.128 19 -0.976 89 0.997 57
    10 0.615 34 -0.471 21 1.712 42 -0.771 90 0.999 30
    20 0.658 48 -0.889 31 2.486 71 -1.349 52 0.999 45
    30 0.735 41 -1.512 43 3.772 39 -1.949 72 0.999 41
    50 0.564 69 -0.798 85 2.221 90 -0.947 26 0.998 14
    注:k0, k1, k2, k3均为模型参数
    下载: 导出CSV
  • [1] 刘松玉. 土力学[M]. 北京: 中国建筑工业出版社, 2005.

    Liu S Y. Soil mechanics[M]. Beijing: China Architecture and Building Press, 2005(in Chinese).
    [2] 杨俊, 童磊, 张国栋. 初始含水率对风化砂改良膨胀土无侧限抗压强度的影响[J]. 地质科技情报, 2014, 33(6): 213-218.

    Yang J, Tong L, Zhang G D. Initial moisture content influence on the unconfined compressive strength of weathered sand improved expansive soil[J]. Geological Science and Technology Information, 2014, 33(6): 213-218(in Chinese with English abstract).
    [3] 胡雪松, 唐朝晖, 万佳文, 等. 煤矸石换填膨胀土路基的沉降研究[J]. 地质科技情报, 2017, 36(6): 261-266.

    Hu X S, Tang C H, Wan J W, et al. Replacing expansive soil with coal gangue in subgrade settlement[J]. Geological Science and Technology Information, 2017, 36(6): 261-266(in Chinese with English abstract).
    [4] Braudeau E, Costantini J M, Bellier G, et al. New device and method for soil shrinkage curve measurement and characterization[J]. Soil Science Society of America Journal, 1999, 63(3): 525-535. doi: 10.2136/sssaj1999.03615995006300030015x
    [5] Giraldez J V, Spositon G, Delgado C. A general soil volume change equation: Ⅰ. The two-parameter model[J]. Soil Science Society of America Journal, 1983, 47(3): 419-422. doi: 10.2136/sssaj1983.03615995004700030005x
    [6] McGarry D, Malafant K W J. The analysis of volume change in unconfined units of oil[J]. Soil Science Society of America Journal, 1987, 51(2): 290-297. doi: 10.2136/sssaj1987.03615995005100020005x
    [7] Tariq A R, Durnford D S. Analytical volume change model for swelling clay soil[J]. Soil Science Society of America Journal, 1993, 57(5): 1183-1187. doi: 10.2136/sssaj1993.03615995005700050003x
    [8] Bolt G H. Physicochemical analysis of compressibility of pure clays[J]. Geotechnique, 1956, 6(2): 86-93. doi: 10.1680/geot.1956.6.2.86
    [9] Simms P, Yanful E. Measurement and estimation of pore shrinkage and pore distribution in a clayey till during soil-water characteristic curve tests[J]. Canadian Geotechnical Journal, 2001, 38(4): 741-754. doi: 10.1139/t01-014
    [10] 谭罗荣. 蒙脱土晶格胀缩对其体积变化的影响[J]. 水文地质工程地质, 1981, 8(6): 5-7, 37. https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG198106001.htm

    Tan L R. Effect of lattice expansion and contraction of montmorillonite on its volume change[J]. Hydrogeology & Engineering Geology, 1981, 8(6): 5-7, 37(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG198106001.htm
    [11] 唐朝生, 施斌, 刘春, 等. 黏性土在不同温度下干缩裂缝的发展规律及形态学定量分析[J]. 岩土工程学报, 2007, 29(5): 743-749.

    Tang C S, Shi B, Liu C, et al. Development law and morphological quantitative analysis of dry shrinkage cracks in clay soil at different temperatures[J]. Chinese Journal of Geotechnical Engineering, 2007, 29(5): 743-749(in Chinese with English abstract).
    [12] 郝建斌, 张焕, 李耕春, 等. 粉煤灰-剑麻纤维复合改良膨胀土强度及裂隙发育特性[J]. 铁道科学与工程学报, 2022, 19(9): 2620-2628. https://www.cnki.com.cn/Article/CJFDTOTAL-CSTD202209018.htm

    Hao J B, Zhang H, Li G C, et al. Strength and fissure development characteristics of fly ash-sisal fiber composite improved expansive soil[J]. Journal of Railway Science and Engineering, 2022, 19(9): 2620-2628(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-CSTD202209018.htm
    [13] 吴继玲, 张小平. 聚丙烯纤维加筋膨胀土强度试验研究[J]. 土工基础, 2010, 24(6): 71-73, 76.

    Wu J L, Zhang X P. Study on strength of polypropylene fiber reinforced expansive soil[J]. Soil Engineering and Foundation, 2010, 24(6): 71-73, 76(in Chinese with English abstract).
    [14] 覃永富, 卢望, 袁梦祥, 等. 巨大芽孢杆菌改良邯郸强膨胀土试验研究[J]. 西南师范大学学报: 自然科学版, 2020, 45(8): 87-95.

    Qin Y F, Lu W, Yuan M X, et al. Experimental study on improved Handan expansive soil by bacillus megaterium[J]. Journal of Southwest China Normal University: Natural Science Edition, 2020, 45(8): 87-95(in Chinese with English abstract).
    [15] 张虎元, 崔素丽, 刘吉胜, 等. 混合型缓冲回填材料膨胀力试验研究[J]. 岩土力学, 2010, 31(10): 3087-3095. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201103008.htm

    Zhang H Y, Cui S L, Liu J S, et al. Experimental study on expansion force of hybrid buffer backfill materials[J]. Rock and Soil Mechanics, 2010, 31(10): 3087-3095(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201103008.htm
    [16] 李国维, 王佳奕, 陈伟, 等. 干湿循环对不同粒径组崩解性砂岩改良膨胀土的影响[J]. 岩土工程学报, 2022, 44(4): 643-651.

    Li G W, Wang J Y, Chen W, et al. Effects of dry-wet cycles on expansive soils modified by disintegrating sandy soft rock with different particle size groups[J]. Chinese Journal of Geotechnical Engineering, 2022, 44(4): 643-651(in Chinese with English abstract).
    [17] 刘昌建, 庄心善. 不同粒径风化砂改良膨胀土的动力特性研究[J]. 陶瓷, 2020(11): 21-23. https://www.cnki.com.cn/Article/CJFDTOTAL-TACI202011004.htm

    Liu C J, Zhuang X S. Study on dynamic characteristics of expansive soil improved by weathered sand with different particle sizes[J]. Ceramics, 2020(11): 21-23(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-TACI202011004.htm
    [18] 李国维, 巩齐齐, 李涛, 等. 崩解性砂软岩改良弱膨胀土性状实验研究[J]. 工程地质学报, 2021, 29(1): 34-43. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ202101004.htm

    Li G W, Gong Q Q, Li T, et al. Experimental study on properties of disintegrating sandy soft rock to improve weak expansive soil[J]. Journal of Engineering Geology, 2021, 29(1): 34-43(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ202101004.htm
    [19] 陈志国, 唐朝生, 叶为民, 等. 水-力耦合条件下膨润土-砂混合物的体变特性研究[J]. 岩土力学, 2017, 38(4): 1041-1051, 1059. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201704016.htm

    Chen Z G, Tang C S, Ye W M, et al. Study on volumetric properties of bentonite-sand mixtures under water-mechanical coupling conditions[J]. Rock and Soil Mechanics, 2017, 38(4): 1041-1051, 1059(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201704016.htm
    [20] 李胜杰, 唐朝生, 张琦, 等. 掺砂率对高放废物处置库中缓冲/回填材料收缩特性的影响[J]. 高校地质学报, 2019, 25(2): 302-308. https://www.cnki.com.cn/Article/CJFDTOTAL-GXDX201902014.htm

    Li S J, Tang C S, Zhang Q, et al. Effect of sand mixing ratio on shrinkage characteristics of buffer/backfill material in high-level radioactive waste repository[J]. Geological Journal of China Universities, 2019, 25(2): 302-308(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-GXDX201902014.htm
    [21] Chertkov V Y. Modelling the shrinkage curve of soil clay pastes[J]. Geoderma, 2003, 112(1/2): 71-95.
    [22] Groenevelt P H, Grant C D. Analysis of soil shrinkage data[J]. Soil & Tillage Research, 2004, 79(1): 71-77.
  • 加载中
图(13) / 表(3)
计量
  • 文章访问数:  407
  • PDF下载量:  39
  • 被引次数: 0
出版历程
  • 收稿日期:  2022-03-09
  • 录用日期:  2022-12-15
  • 修回日期:  2022-12-13

目录

    /

    返回文章
    返回