膨胀土裂隙发育的厚度效应试验研究

doi:10.11779/CJGE202010018

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摘要膨胀土的裂隙开展受到许多因素的影响,包括自身的土体性质,环境状况,边界条件、土体尺寸等。厚度对膨胀土等黏性土体的开裂规律具有重要的影响,为了探究这种重要因素在膨胀土失水收缩开裂过程中的具体影响规律,试验设置了4个具有不同厚度的大直径圆形泥浆试样。运用图像处理技术,通过记录试样的裂隙演化过程及质量的变化,定量分析裂隙面积分形维数、长度分形维数等指标随含水率下降的动态变化关系。试验结果发现：①厚度对膨胀土失水收缩开裂及裂隙扩展过程有明显影响,厚度较小的试样其裂隙发育充分,裂隙密集细长而纹理丰富;厚度较大的试样裂隙发育单一,裂隙宽大而边界效应明显,通过提出厚度和试样直径的比值,可以初步预估试样的裂隙发育情况;②裂隙面积分形维数受厚度的影响较小,而裂隙长度分形维数受厚度的影响较大,结合两者可以有效地对裂隙形态及分布进行表征,裂隙最终的长度分形维数一般在1~1.5,而面积分形维数基本维持在1.6~1.7。此外,结合土体开裂的张拉破坏理论以及试样的收缩蒸发情况,对厚度影响下的土体开裂差异进行了理论分析,进一步探究了裂隙的扩展规律。

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	骆赵刚
	汪时机
	张继伟
	杨振北

关键词 ：膨胀土, 厚度效应, 裂隙演化, 分形维数, 定量化

Abstract：The crack development of expansive soil is affected by many factors, including soil properties, environmental conditions, boundary conditions and soil sizes. Crack evolution is greatly influenced by thickness. In order to explore the specific influence rules of the thickess in the whole process of water loss shrinkage and cracking of expansive soil, four large-diameter circular mud samples with different thicknesses are prepared in the experiment. With the help of image processing technology, the dynamic change relationship of the basic crack indexes with the decrease of water content are quantitatively analyzed by recording the evolution process of cracks in the samples. The experimental results show that the process of water loss shrinkage and crack expansion of expansive soil are significantly affected by the thickness. The crack of the sample with smaller thickness is fully developed, and it is long and thin. However, the sample with larger thickness has a single wide crack and is affected by obvious boundary effect. The development of the cracks is preliminarily estimated by the ratio of thickness to diameter. In addition, the morphology and distribution of the cracks can be characterized effectively by combining the fractal dimensions of area and length. The fractal dimension of crack length is generally about 1~1.5, while the surface integral dimension is basically maintained at 1.6~1.7. Moreover, based on the tensile failure theory of soil cracking and the shrinkage and evaporation of the samples, the difference of soil cracking affected by the thickness is theoretically analyzed, and the expansion rules of cracks are further explored.

Key words： expansive soil thickness effect crack evolution fractal dimension quantification

收稿日期: 2019-12-09

ZTFLH:

TU443

基金资助:国家自然科学基金项目（11972311,11572262）; 中央高校基本业务费专项资金项目（XDJK2018AB003）

通讯作者: *（E-mail：shjwang@swu.edu.cn）

作者简介: 骆赵刚(1996— ),男,硕士研究生,主要从事土体裂隙的定量化方面的研究。E-mail: lzg319818@email. swu.edu.cn。

引用本文:

骆赵刚, 汪时机, 张继伟, 杨振北. 膨胀土裂隙发育的厚度效应试验研究[J]. 岩土工程学报, 2020, 42(10): 1922-1930. LUO Zhao gang, WANG Shi ji, ZHANG Ji wei, YANG Zhen bei. Thickness effect on crack evolution of expansive soil. Chinese J. Geot. Eng., 2020, 42(10): 1922-1930.

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http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/10.11779/CJGE202010018 或 http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/Y2020/V42/I10/1922

[1] 袁俊平, 蔺彦玲, 丁鹏, 等. 裂隙诱导各向异性对边坡降雨入渗的影响[J]. 岩土工程学报, 2016, 38(1): 76-82.
(YUAN Jun-ping, LIN Yan-ling, DING Peng, et al.Influence of anisotropy induced by fissures on rainfall infiltration of slopes[J]. Chinese Journal of Geotechnical Engineering, 2016, 38(1): 76-82. (in Chinese))
[2] 郑少河, 姚海林, 葛修润. 裂隙性膨胀土饱和-非饱和渗流分析[J]. 岩土力学, 2007, 28(增刊1): 281-285.
(ZHENG Shao-he, YAO Hai-lin, GE Xiu-run.Analysis of saturated and unsaturated seepage of cracked expansive soil[J]. Rock and Soil Mechanics, 2007, 28(S1): 281-285. (in Chinese))
[3] 蔡正银, 朱洵, 黄英豪, 等. 湿干冻融耦合循环作用下膨胀土裂隙演化规律[J]. 岩土工程学报, 2019, 41(8): 1381-1389.
(CAI Zheng-yin, ZHU Xun, HUANG Ying-hao, et al.Evolution rules of fissures in expansive soils under cyclic action of coupling wetting-drying and freeze-thaw[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(8): 1381-1389. (in Chinese))
[4] 殷宗泽, 徐彬. 反映裂隙影响的膨胀土边坡稳定性分析[J]. 岩土工程学报, 2011, 33(3): 454-459.
(YIN Zong-ze, XU Bin.Slope stability of expansive soil under fissure influence[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(3): 454-459. (in Chinese))
[5] 龚壁卫, 程展林, 胡波, 等. 膨胀土裂隙的工程特性研究[J]. 岩土力学, 2014, 35(7): 1825-1830.
(GONG Bi-wei, CHENG Zhan-lin, HU Bo, et al.Research on engineering properties of fissures in expansive soil[J]. Rock and Soil Mechanics, 2014, 35(7): 1825-1830. (in Chinese))
[6] 陈正汉, 郭楠. 非饱和土与特殊土力学及工程应用研究的新进展[J]. 岩土力学, 2019, 40(1): 1-54.
(CHEN Zheng-han, GUO Nan.New developments of mechanics and application for unsaturated soils and special soils[J]. Rock and Soil Mechanics, 2019, 40(1): 1-54. (in Chinese))
[7] 崔玉军, 陈宝. 高放核废物地质处置中工程屏障研究新进展[J]. 岩石力学与工程学报, 2006, 25(4): 842-847.
(CUI Yu-jun, CHEN Bao.Recent advances in research on engineered barrier for geological disposal of high-level radioactive nuclear waste[J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(4): 842-847. (In Chinese))
[8] 殷宗泽, 袁俊平, 韦杰, 等. 论裂隙对膨胀土边坡稳定的影响[J]. 岩土工程学报, 2012, 34(12): 2155-2161.
(YIN Zong-ze, YUAN Jun-ping, WEI Jie, et al.Influences of fissures on slope stability of expansive soil[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(12): 2155-2161. (in Chinese))
[9] 蔡正银, 陈皓, 黄英豪, 等. 考虑干湿循环作用的膨胀土渠道边坡破坏机理研究[J]. 岩土工程学报, 2019, 41(11): 1977-1982.
(CAI Zheng-yin, CHEN Hao, HUANG Ying-hao, et al.Failure mechanism of canal slopes of expansive soils considering action of wetting-drying cycles[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(11): 1977-1982. (in Chinese))
[10] 黎伟, 刘观仕, 汪为巍, 等. 湿干循环下压实膨胀土裂隙扩展规律研究[J]. 岩土工程学报, 2014, 36(7): 1302-1308.
(LI Wei, LIU Guan-shi, WANG Wei-wei, et al.Crack propagation law of compacted expansive soils under wetting-drying cycles[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(7): 1302-1308. (in Chinese))
[11] 易顺民, 黎志恒, 张延中. 膨胀土裂隙结构的分形特征及其意义[J]. 岩土工程学报, 1999, 21(3): 294-298.
(YI Shun-min, LI Zhi-heng, ZHANG Yan-zhong.The fractal characteristics of fractures in expansion soil and its significance[J]. Chinese Journal of Geotechnical Engineering, 1999, 21(3): 294-298. (in Chinese))
[12] 曹玲, 王志俭, 张振华. 降雨-蒸发条件下膨胀土裂隙演化特征试验研究[J]. 岩石力学与工程学报, 2016, 35(2): 413-421.
(CAO Ling, WANG Zhi-jian, ZHANG Zhen-hua.Experimental research of cracking process of expansive soil under rainfall infiltration and evaporation[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(2): 413-421. (in Chinese))
[13] 唐朝生, 施斌, 刘春. 膨胀土收缩开裂特性研究[J]. 工程地质学报, 2012, 20(5): 663-673.
(TANG Chao-sheng, SHI Bin, LIU Chun.Study on desiccation cracking behaviour of expansive soil[J]. Journal of Engineering Geology, 2012, 20(5): 663-673. (in Chinese))
[14] UDAY K V, SINGH D N.Investigation on cracking characteristics of fine-grained soils under varied environmental conditions[J]. Drying Technology, 2013, 31(11): 1255-1266.
[15] TANG C S, SHI B, LIU C, et al.Influencing factors of geometrical structure of surface shrinkage cracks in clayey soils[J]. Engineering Geology, 2008, 101(3/4): 204-217.
[16] 汪为巍, 黎伟, 易远. 南阳膨胀土裂隙发育规律研究[J]. 地下空间与工程学报, 2015, 11(6): 1437-1443.
(WANG Wei-wei, LI Wei, YI Yuan.Study on the cracking law of nanyang expansive soil[J]. Chinese Journal of Underground Space and Engineering, 2015, 11(6): 1437-1443. (in Chinese))
[17] 刘观仕, 陈永贵, 张贵保, 等. 压实条件对膨胀土裂隙发育影响的试验研究[J]. 长江科学院院报, 2019, 36(11): 91-97.
(LIU Guan-shi, CHEN Yong-gui, ZHANG Gui-bao, et al.Crack propagation law of compacted expansive soil with various original compactness and water content[J]. Journal of Yangtze River Scientific Research Institute, 2019, 36(11): 91-97. (in Chinese))
[18] 林沛元, 汤连生, 桑海涛, 等. 分形几何在岩土力学研究中的过去、现在与未来[J]. 西北地震学报, 2011, 33(增刊1): 24-29.
(LIN Pei-yuan, TANG Lian-sheng, SANG Hai-tao, et al.Fractal geometry in the past,present and future research of rock and soil mechanics[J]. Northwestern Seismological Journal, 2011, 33(S1): 24-29. (in Chinese))
[19] 刘昌黎, 唐朝生, 李昊达, 等. 界面粗糙度对土体龟裂影响的试验研究[J]. 工程地质学报, 2017, 25(5): 1314-1321.
(LIU Chang-li, TANG Chao-sheng, LI Hao-da, et al.Experimental study on the effect of interfacial roughness on desiccation cracking behavior of soil[J]. Journal of Engineering Geology, 2017, 25(5): 1314-1321. (in Chinese))
[20] 曾浩, 唐朝生, 刘昌黎, 等. 膨胀土干燥过程中收缩应力的测试与分析[J]. 岩土工程学报, 2019, 41(4): 717-725.
(ZENG Hao, TANG Chao-sheng, LIU Chang-Li, et al.Measurement and analysis of shrinkage stress of expansive soils during drying process[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(4): 717-725. (in Chinese))
[21] 张家俊, 龚壁卫, 胡波, 等. 干湿循环作用下膨胀土裂隙演化规律试验研究[J]. 岩土力学, 2011, 32(9): 2729-2734.
(ZHANG Jia-jun, GONG Bi-wei, HU Bo, et al.Study of evolution law of fissures of expansive clay under wetting and drying cycles[J]. Rock and Soil Mechanics, 2011, 32(9): 2729-2734. (in Chinese))
[22] 冉龙洲, 宋翔东, 唐朝生. 干燥过程中膨胀土抗拉强度特性研究[J]. 工程地质学报, 2011, 19(4): 620-625.
(RAN Long-zhou, SONG Xiang-dong, TANG Chao-sheng.Laboratorial investigation on tensile strength of expansive soil during drying[J]. Journal of Engineering Geology, 2011, 19(4): 620-625. (in Chinese))
[23] 蔡国庆, 车睿杰, 孔小昂, 等. 非饱和砂土抗拉强度的试验研究[J]. 水利学报, 2017, 48(5): 623-630.
(CAI Guo-qing, CHE Rui-jie, KONG Xiao-ang, et al.Experimental investigation on tensile strength of unsaturated fine sands[J]. Journal of Hydraulic Engineering, 2017, 48(5): 623-630. (in Chinese))
[24] 刘观仕, 陈永贵, 曾宪云, 等. 环境湿度与温度对压实膨胀土裂隙发育影响试验研究[J]. 岩土工程学报, 2020, 42(2): 260-268.
(LIU Guan-shi, CHEN Yong-gui, ZENG Xian-yun, et al.Effects of ambient air humidity and temperature on crack development of compacted expansive soil[J]. Chinese Journal of Geotechnical Engineering, 2020,42(2): 260-268. (in Chinese))