渗滤液饱和膨润土掺砂混合土的膨胀与渗透特性

doi:10.12066/j.issn.1007-2861.2105

摘要/Abstract

摘要：

对膨润土掺砂混合土非饱和压实样,在不同温度和竖向应力为 50kPa 的条件下分别用纯水和渗滤液进行饱和膨胀试验以及饱和后的固结试验.利用变水头试验和固结试验,测量当渗滤液作为孔隙液体时不同掺砂率混合土的渗透系数. 试验结果表明:① 饱和液体种类对膨润土掺砂混合土膨胀变形的影响较大,用渗滤液饱和膨润土掺砂混合土的最终膨胀率比用纯水饱和的要小;② 当掺砂率较低时渗滤液饱和混合土的膨胀力比纯水饱和的小,当掺砂率为 50% 时 2 种液体饱和膨润土掺砂混合土的膨胀力几乎相等,混合土的膨胀变形和膨胀力随温度升高而减小;③ 在孔隙比相近的条件下纯水饱和混合土的渗透系数比渗滤液饱和的稍大,随温度升高渗透系数增大; ④ 在相同孔隙比条件下,固结试验方法测定的渗透系数小于变水头试验测定的数值.

关键词: 膨润土掺砂混合土, 渗滤液, 膨胀, 温度, 渗透系数

Abstract:

A series of swelling tests were carried out on bentonite and sand mixtures saturated by pure water and landfill leachate; the mixtures sported different sand mixing rates. The tests were carried out under various temperatures and a vertical pressure of50 kPa. Furthermore, the swelling tests were followed by consolidation and falling head tests to measure hydraulic conductivity. The following test results were obtained. (1) The liquid used for saturating the unsaturated soils significantly influenced the swelling characteristics of the bentonite and sand mixture. The final swelling rate of the mixtures saturated by the leachate was less than that of the mixtures saturated by pure water. (2) When the sand mixing rate was low, the swelling pressure of the mixture saturated by the leachate was smaller than that of the mixture saturated by water. When the sand mixing rate was 50%, the swelling pressures of the mixtures saturated by leachate and water were nearly identical. Moreover, the swelling pressures and final swelling rates of the mixtures increased with decreasing temperature. (3) For similar void ratios, the hydraulic conductivity of the mixtures saturated using water was slightly higher than that of the mixtures saturated using leachate. Furthermore, the hydraulic conductivities increased with increasing temperature. (4) For similar void ratios, the hydraulic conductivity measured via consolidation tests was lower than that measured using the falling head test.

Key words: bentonite and sand mixture, leachate, swelling, temperature, hydraulic conductivity

中图分类号:

TU443

阮坤林, 孙德安, 傅贤雷. 渗滤液饱和膨润土掺砂混合土的膨胀与渗透特性[J]. 上海大学学报(自然科学版), 2020, 26(6): 989-1000.

RUAN Kunlin, SUN Dean, FU Xianlei. Swelling characteristics and hydraulic conductivities of bentonite and sand mixtures saturated with landfill leachate[J]. Journal of Shanghai University（Natural Science Edition）, 2020, 26(6): 989-1000.

图/表 12

表1

表2

图1

图2

图3

图4

图5

图6

图7

图8

图9

图10

参考文献 28

[1]	姚道坤. 中国膨润土矿床及其开发应用[M]. 北京: 地质出版社, 1994.
[2]	陈云敏, 施建勇, 朱伟, 等. 环境岩土工程研究综述[J]. 土木工程学报, 2012,45(4):165-182.
[3]	张文杰, 贾文强, 张改革, 等. 黏土-膨润土屏障中氯离子对流扩散规律研究[J]. 岩土工程学报, 2013,35(11):2076-2081.
[4]	范日东, 杜延军, 陈左波, 等. 受铅污染的土-膨润土竖向隔离墙材料的压缩及渗透特性试验研究[J]. 岩土工程学报, 2013,35(5):841-848.
[5]	许四法, 吴雪辉, 胡琦, 等. Ca$^{2+}$ 浓度对膨润土掺砂混合土渗透性能的影响[J]. 岩土工程学报, 2017,39(6):1145-1150.
[6]	Granthama G, Robinsona H. Instrumentation and monitoring of a bentonite landfillliner[J]. Waste Management and Research, 1988,6(2):125-139. doi: 10.1177/0734242X8800600122
[7]	Chapuis R P. Sand-bentonite liners: predicting permeability from laboratory tests[J]. Canadian Geotechnical Journal, 1990,27(1):47-57. doi: 10.1139/t90-005
[8]	Demdoum A, Gueddouda M K, Goual I. Effect of water and leachate on hydraulic behavior of compacted bentonite, calcareous sand and tuff mixtures for use as landfill liners[J]. Geotechnical and Geological Engineering, 2017,35(6):2677-2696. doi: 10.1007/s10706-017-0270-4
[9]	Sari K, Chai J C. Self healing capacity of geosynthetic clay liners and influencing factors[J]. Geotextiles and Geomembranes, 2013,41:64-71. doi: 10.1016/j.geotexmem.2013.08.006
[10]	Ören A H, Akar R C. Swelling and hydraulic conductivity of bentonites permeated with landfill leachates[J]. Applied Clay Science, 2017,142:81-89. doi: 10.1016/j.clay.2016.09.029
[11]	Kolstad D C, Benson C H, Edil T B. Hydraulic conductivity and swell of nonprehydrated geosynthetic clay liners permeated with multispecies inorganic solutions[J]. Journal of Geotechnical and Geoenvironmental Engineering. 2004,130(12):1236-1249. doi: 10.1061/(ASCE)1090-0241(2004)130:12(1236)
[12]	蒋江红, 孙德安. 温度对高庙子膨润土浸水膨胀特性的影响[J]. 上海大学学报(自然科学版), 2017,23(5):762-771.
[13]	Rowe R K. Long-term performance of contaminant barrier systems[J]. Geotechnique, 2005,55(9):631-678. doi: 10.1680/geot.2005.55.9.631
[14]	芮巍, 艾英钵, 夏璐, 等. 淋滤液饱和掺砂膨润土的压缩固结特性试验研究[J]. 河南科学, 2015,33(10):1782-1788.
[15]	Mishra A K, Ohtsubo M, Li L, et al. Controlling factors of the swelling of various bentonites and their correlations with the hydraulic conductivity of soil-bentonite mixtures[J]. Apply Clay Science, 2011,52(1/2):78-84.
[16]	Yamada K, Watabe Y, Saitoh K. Hydraulic conductivity and compressibility of mixtures of Nagoya clay with sand or bentonite[J]. Geotechnique, 2011,61(3):211-219. doi: 10.1680/geot.8.P.087
[17]	范奥尔芬H. 粘土胶体化学导论[M]. 北京: 农业出版社, 1979.
[18]	Bradshaw S L, Benson C H. Effect of municipal solid waste leachate on hydraulic conductivity and exchange complex of geosynthetic clay liners[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2014,140(4):04013038. doi: 10.1061/(ASCE)GT.1943-5606.0001050
[19]	孙文静, 刘仕卿, 孙德安, 等. 掺砂率对膨润土与砂混合物膨胀特性的影响[J]. 岩土力学, 2016,37(6):1642-1648.
[20]	Villar M V, Rgomez E R, Lloret A. Experimental investigation into temperature effect on hydro mechanical behaviors of bentonite[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2010,2(1):71-78
[21]	谈云志, 李辉, 王培荣, 等. 膨润土受热作用后的水-力性能研究[J]. 岩土力学, 2019,40(2):489-496.
[22]	何俊, 阮晓晨, 胡晓瑾, 等. 温度和模拟渗滤液作用下黏土的渗透性能研究[J]. 水文地质工程地质, 2017,44(1):116-121.
[23]	陈志国, 唐朝生, 叶为民, 等. 水-力耦合条件下膨润土掺砂混合物的体变特性研究[J]. 岩土力学, 2017,38(4):1041-1051.
[24]	Rauen T L, Benson C H. Hydraulic conductivity of a geosynthetic clay liner permeated with leachate from a landfill with leachate recirculation[C]// Proceeding of Geoamericas. 2008: 76-83.
[25]	陈萍, 林伟岸, 占鑫杰, 等. 渗滤液浸泡对深度脱水污泥强度和渗透性能的影响[J]. 岩土力学, 2013,34(2):337-341.
[26]	Shirazi S M, Kazama H, Salman F A, et al. Permeability and swelling characteristics of bentonite[J]. International Journal of the Physical Sciences, 2010,5(11):1647-1659.
[27]	Mesri G, Olson R E. Mechanisms controlling the permeability of clays[J]. Clays and Clay Minerals, 1971,19:151-158. doi: 10.1346/CCMN
[28]	中华人民共和国住房和城乡建设部. GB/50869——2013 生活垃圾卫生填埋处理技术规范[S]. 北京: 中国计划出版社, 2013.