• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊
  • Scopus数据库收录期刊

基于围压柔性加载的土石混合体大型三轴试验离散元模拟研究

张强, 汪小刚, 赵宇飞, 周家文, 孟庆祥, 周梦佳

张强, 汪小刚, 赵宇飞, 周家文, 孟庆祥, 周梦佳. 基于围压柔性加载的土石混合体大型三轴试验离散元模拟研究[J]. 岩土工程学报, 2019, 41(8): 1545-1554. DOI: 10.11779/CJGE201908020
引用本文: 张强, 汪小刚, 赵宇飞, 周家文, 孟庆祥, 周梦佳. 基于围压柔性加载的土石混合体大型三轴试验离散元模拟研究[J]. 岩土工程学报, 2019, 41(8): 1545-1554. DOI: 10.11779/CJGE201908020
ZHANG Qiang, WANG Xiao-gang, ZHAO Yu-fei, ZHOU Jia-wen, MENG Qing-xiang, ZHOU Meng-jia. Discrete element simulation of large-scale triaxial tests on soil-rock mixtures based on flexible loading of confining pressure[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(8): 1545-1554. DOI: 10.11779/CJGE201908020
Citation: ZHANG Qiang, WANG Xiao-gang, ZHAO Yu-fei, ZHOU Jia-wen, MENG Qing-xiang, ZHOU Meng-jia. Discrete element simulation of large-scale triaxial tests on soil-rock mixtures based on flexible loading of confining pressure[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(8): 1545-1554. DOI: 10.11779/CJGE201908020

基于围压柔性加载的土石混合体大型三轴试验离散元模拟研究  English Version

基金项目: 国家重点研发计划项目(2017YFC1501100); 国家自然科学基金项目(11772118); 博士后科学基金项目(2017M620838); 四川大学水力学与山区河流开发保护国家重点实验室开放合作基金项目(SKHL1725)
详细信息
    作者简介:

    张 强(1986— ),男,博士后,主要从事复杂岩土体多尺度灾变机理与数值模拟等方面的研究。E-mail:zhangq@iwhr.com。

  • 中图分类号: TU43

Discrete element simulation of large-scale triaxial tests on soil-rock mixtures based on flexible loading of confining pressure

  • 摘要: 综合运用计算机三维扫描与随机模拟技术,建立了不同块石含量和空间分布的土石混合体三维随机细观结构模型和离散元模型,考虑围压柔性加载,基于柔性黏结颗粒膜方法,采用颗粒流程序对不同土石混合体试样进行了不同围压下的大型离散元三轴试验模拟,研究了块石含量和空间分布对土石混合体力学特性和变形破坏规律的影响。数值模拟结果表明:土石混合体的强度和抵抗变形的能力随含量和围压的增大而增强,且在相同含石量下,受内部块石空间分布的影响,试样的内摩擦角和黏聚力虽会表现出一定的离散性,但总体上,内摩擦角随着含石量增加基本呈线性增加,而黏聚力却随着含石量增加逐渐减小;在围压柔性加载下,土石混合体试样表现为鼓胀变形破坏,破坏后形成的剪切带为一个曲折条带,形态上呈非对称的X形分布,厚度约为试样高度的1/3~1/2倍,且试样的破坏形态及内部剪切带大小和分布形态不仅受块石含量和空间分布影响,而且也取决于围压大小;土石混合体试样在破坏过程中内部剪切带的形成是伴随局部颗粒的转动开始的,在应变到达峰值应变时,局部发生转动的颗粒相互连接贯通,此时剪切带已基本形成,此后随着应变继续增加,受峰后鼓胀变形的影响,试样内部颗粒的转动仍会发生一定的变化,同时伴随着剪切带大小和分布形态也发生相应的变化。
    Abstract: Based on the computer three-dimensional scanning and stochastic simulation technologies, the three-dimensional random meso-structure models and discrete element models for soil-rock mixture (S-RM) samples with different stone contents and spatial distributions are established. Considering the flexible loading of confining pressure, the large-scale numerical triaxial tests on the S-RM samples under different confining pressures based on the flexibly-bonded particles method are conducted by particle flow code, and the effects of the stone content and spatial distribution on their mechanical properties and deformation and failure characteristics are studied. The numerical simulation results show that the strengths and deformation resistibility capacities of the S-RM samples increase with the increase of stone content and confining pressure, and their internal friction angles and cohesions vary to a certain extent under the same content but different spatial distributions of stones. However on the whole, the internal friction angle increases linearly with the increase of stone content, while the cohesion decreases. Under the flexible loading of confining pressure, the S-RM samples show bulging deformation and failure mode, and the shear band formed after failure is a meandering strip with an asymmetric X-shaped distribution, whose thickness is about 1/3~1/2 times the height of the S- RM samples. Moreover, the failure mode and the thickness and shape of shear band are affected by the stone content and spatial distribution and the confining pressure. The shear band formation is accompanied by the rotations of the local particles in the S-RM sample. When the strain reaches the peak strain, the locally rotating particles are connected to each other, indicating that the shear band has basically formed at this time. Since then, as the axial strain increases continually, the rotations of the internal particles still change because of the effect of the bulging deformation after the peak, and the thickness and shape of the shear band also change accordingly.
  • [1] 油新华. 土石混合体的随机结构模型及其应用研究[D]. 北京: 北京交通大学, 2002.
    (YOU Xin-hua.Stochastic structural model of the earth-rock aggregate and its application[D]. Beijing: Beijing Jiaotong University, 2002. (in Chinese))
    [2] 孙华飞, 鞠杨, 王晓斐, 等. 土石混合体变形破坏及细观机理研究的进展[J]. 中国科学: 技术科学, 2014, 44(2): 172-181.
    (SUN Hua-fei, JU Yang, WANG Xiao-fei, et al.Review of the study on deformation, failure and the mesomechanisms of rock-soil mixture (RSM)[J]. Scientia Sinica: Technologica, 2014, 44(2): 172-181. (in Chinese))
    [3] 王宇, 李晓, 赫建明, 等. 土石混合体细观特性研究现状及展望[J]. 工程地质学报, 2014, 22(1): 112-123.
    (WANG Yu, LI Xiao, HAO Jian-ming, et al.Research status and prospect of rock and soil aggregate[J]. Journal of Engineering Geology, 2014, 22(1): 112-123. (in Chinese))
    [4] 夏加国, 胡瑞林, 祁生文, 等. 含超径颗粒土石混合体的大型三轴剪切试验研究[J]. 岩石力学与工程学报, 2017, 36(8): 2031-2039.
    (XIA Jia-guo, HU Rui-lin, QI Sheng-wen, et al.Large-scale triaxial shear testing of soil rock mixtures containing oversized particles[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(8): 2031-2039. (in Chinese))
    [5] 王江营, 曹文贵, 蒋中明, 等. 不同应力路径下土石混填体变形力学特性大型三轴试验研究[J]. 岩土力学, 2016, 37(2): 424-430.
    (WANG Jiang-ying, CAO Wen-gui, JIANG Zhong-ming, et al.Large-scale triaxial tests on deformation and mechanical behavior of soil-rock aggregate mixture under different stress paths[J]. Rock and Soil Mechanics, 2016, 37(2): 424-430. (in Chinese))
    [6] 金磊, 曾亚武, 张森. 块石含量及形状对胶结土石混合体力学性能影响的大型三轴试验[J]. 岩土力学, 2017, 38(1): 141-149.
    (JIN Lei, ZENG Ya-wu, ZHANG Sen.Large scale triaxial tests on effects of rock block proportion and shape on mechanical properties of cemented soil-rock mixture[J]. Rock and Soil Mechanics, 2017, 38(1): 141-149. (in Chinese))
    [7] 金磊, 曾亚武, 李欢, 等. 基于不规则颗粒离散元的土石混合体大三轴数值模拟[J]. 岩土工程学报, 2015, 37(5): 829-838.
    (JIN Lei, ZENG Ya-wu, LI Huan, et al.Numerical simulation of large-scale triaxial tests on soil-rock mixture based on DEM of irregularly shaped particles[J]. Chinese Journal of Geotechnical Engineering, 2015, 37(5): 829-838. (in Chinese))
    [8] 王新. 土石混合体力学特性影响因素及破坏机制研究[D]. 武汉: 长江科学院, 2010.
    (WANG Xin.Research on influence factors of mechanical characteristics and failure mechanism of soil-rock mixture[D]. Wuhan: Yangtze River Scientific Research Institute, 2010. (in Chinese))
    [9] 张强, 汪小刚, 赵宇飞, 等. 不同围压加载方式下土石混合体变形破坏机制颗粒流模拟研究[J]. 岩土工程学报, 2018, 40(11): 2051-2060.
    (ZHANG Qiang, WANG Xiao-gang, ZHAO Yu-fei, et al.Particle flow modelling of deformation and failure mechanism of soil-rock mixture under different loading modes of confining pressure[J]. Chinese Journal of Geotechnical Engineering, 2018, 40(11): 2051-2060. (in Chinese))
    [10] ZHAO X L, EVANS T M.Discrete simulations of laboratory loading conditions[J]. International Journal of Geomechanics, 2009, 9(4): 169-178.
    [11] DE B J P, MCDOWELL G R, WANATOWSKI D. Discrete element modelling of a flexible membrane for triaxial testing of granular material at high pressures[J]. Géotechnique Letters, 2012, 2(2): 199-203.
    [12] CIL M B, ALSHIBLI K A.3D analysis of kinematic behavior of granular materials in triaxial testing using DEM with flexible membrane boundary[J]. Acta Geotechnica, 2014, 9(2): 287-298.
    [13] 金磊, 郑亚武. 基于三维柔性薄膜边界的土石混合体大型三轴试验颗粒离散元模拟[J]. 岩土工程学报, 2018, 40(12): 2296-2304.
    (JIN Lei, ZHENG Ya-wu.Numerical simulation of large-scale triaxial test on soil-rock mixture using DEM with three-dimensional flexible membrane boundary[J]. Chinese Journal of Geotechnical Engineering, 2018, 40(12): 2296-2304. (in Chinese))
    [14] XU W J, HU L M, GAO W.Random generation of the meso-structure of a soil-rock mixture and its application in the study of the mechanical behavior in a landslide dam[J]. International Journal of Rock Mechanics & Mining Sciences, 2016, 86: 166-178.
    [15] 张强. 大型冰水滑坡堆积体工程力学特性及应用研究[D]. 南京: 河海大学, 2016.
    (ZHANG Qiang.Study on engineering mechanical properties of large-scale outwash landslide deposits and its application[D]. Nanjing: Hohai University, 2016. (in Chinese))
    [16] 徐文杰, 王识. 基于真实块石形态的土石混合体细观力学三维数值直剪试验研究[J]. 岩石力学与工程学报, 2016, 35(10): 2152-2160.
    (XU Wen-jie, WANG Shi.Meso- mechanics of soil-rock mixture with real shape of rock blocks based on 3D numerical direct shear test[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(10): 2152-2160. (in Chinese))
    [17] MEDLEY E W.The engineering characterization of mélanges and similar block-in-matrix rocks(bimrocks)[D]. Berkeley: University of California, 1994.
    [18] Itasca Consulting Group Inc. PFC 5.0 help manual[M]. Minneapolis: Itasca Consulting Group Inc, 2014.
    [19] XU W J, XU Q, HU R L.Study on the shear strength of soil-rock mixture by large scale direct shear test[J]. International Journal of Rock Mechanics & Mining Sciences, 2011,48(8): 1235-1247.
    [20] HALL S A, BORNERT M, DESRUES J, et al.Discrete and continuum analysis of localized deformation in sand using X-ray CT and volumetric digital image correlation[J]. Géotechnique, 2010, 60(5): 11-20.
计量
  • 文章访问数: 
  • HTML全文浏览量:  0
  • PDF下载量: 
  • 被引次数: 0
出版历程
  • 收稿日期:  2018-08-06
  • 发布日期:  2019-08-24

目录

    /

    返回文章
    返回