平面应变条件下含孔洞土样受内压作用的变形破坏过程
CSTR:
作者:
中图分类号:

TU454

基金项目:

国家自然科学基金(51574144);辽宁省百千万人才工程(2017)


Experimental measurements of deformation and failure processes of plane strain clay specimens with holes and subjected to internal pressures
Author:
  • 摘要
  • | |
  • 访问统计
  • |
  • 参考文献 [11]
  • |
  • 相似文献 [20]
  • | | |
  • 文章评论
    摘要:

    在不同加载速率下,利用自主研制的平面应变模型加载及观测系统对平面应变条件下含孔洞土样进行双轴压缩实验。垂压由试验机施加,土样受到的内压和侧压作用由气囊施加。在对土样施加内压和侧压后、进行位移控制加载前,操控数码相机对喷涂了散斑的土样表面图像进行拍摄,以记录土样在位移控制加载过程中的全部变形过程。利用数字图像相关方法获得土样的位移场,利用能较好滤掉位移场噪声的局部位移最小二乘拟合方法获得最大剪切应变的分布及演变规律。为了定量获得最大剪切应变且分析方便,根据清晰剪切带位置,布置曲折测线并在其两侧布置平直测线。研究发现:当加载速率较低且纵向应变达到一定值时,拉破坏导致土样的孔洞顶部和底部发展出高角度应变局部化带,而当加载速率较高时,未出现上述现象;当纵向应变较高时,在孔洞表面附近,随着向孔洞表面的逐渐靠近,大多数剪切带内测线上的最大剪切应变逐渐增加,而大多数带外测线上的最大剪切应变则逐渐下降;当纵向应变较高时,在离孔洞表面较远处,随着向孔洞表面的逐渐靠近,大多数剪切带内测线上的最大剪切应变逐渐增加,而大多数带外测线上的最大剪切应变则变化复杂。

    Abstract:

    Biaxial compressive tests of cuboid low liquid-limit clay specimens with holes under plane strain for different loading rates were conducted by use of designed loading and measuring system. The vertical pressures were applied by the testing machine, and the internal and lateral pressures were applied by gasbags. To obtain the full deformation process of clay specimens with holes during the displacement-controlled loading process, a digital camera is used to record speckle images of clay specimens with holes after internal and lateral pressures were applied and before the displacement-controlled loading was conducted. Displacements can be abfained by use of the digital image correlation method. Distributions and evolution of the maximum shear strains were measured by use of least-square fitting of local displacements that can better eliminate noises in displacements. To obtain quantitative maximum shear strains, curve monitored lines were arranged according to positions of clear shear bands, and two straight monitored lines were arranged at both sides of each curve monitored line. The following results were obtained:when the longitudinal strain reaches a certain value, high-angle strain localization bands from the top and bottom of the hole for lower loading rates developed, due to tensile failure. While there are no high-angle strain localization bands for higher loading rates, when the longitudinal strain shear strains of most monitored lines outside shear bands have decreasing tendencies as they approach the hole surface. When the longitudinal strain is higher and monitored lines are far away from the hole surface, the maximum shear strains of most monitored lines in shear bands have decreasing tendencies as they approach the hole surface. The change of the maximum shear strains of monitored lines outside shear bands are complex as they approach the hole surface.

    参考文献
    [1] 宋力, 宋万增, 高玉琴, 等. 引黄涵闸引水涵洞地基竖向应力分布规律[J]. 人民黄河, 2015, 37(1): 126-129. SONG L, SONG W Z, GAO Y Q, et al. Preliminary study about foundation vertical stress distribution on diversion culvert of the Yellow River sluice [J]. Yellow River, 2015, 37(1): 126-129. (in Chinese)
    [2] 魏建军. 考虑剪胀和软化的巷道围岩弹塑性分析[J]. 土木建筑与环境工程, 2013, 35(3): 7-11. WEI J J. Elastic-plastic analysis of surrounding rocks considering material dilatancy and softening [J]. Journal of Civil, Architectural & Environmental Engineering, 2013, 35(3): 7-11. (in Chinese)
    [3] VITONE C, VIGGIANI G, COTECCHIA F, et al. Localized deformation in intensely fissured clays studied by 2D digital image correlation [J]. Acta Geotechnica, 2013, 8(3): 247-263.
    [4] ALIKARAMI R, TORABI A. Micro-texture and petrophysical properties of dilation and compaction shear bands in sand [J]. Geomechanics for Energy and the Environment, 2015, 3: 1-10.
    [5] 马少鹏, 周辉. 岩石破坏过程中试件表面应变场演化特征研究[J]. 岩石力学与工程学报, 2008, 27(8): 1667-1673. MA S P, ZHOU H. Surface strain field evolution of rock specimen during failure process [J]. Chinese Journal of Rock Mechanics and Engineering, 2008, 27(8): 1667-1673.(in Chinese)
    [6] 刘招伟, 李元海. 含孔洞岩石单轴压缩下变形破裂规律的实验研究[J]. 工程力学, 2010, 27(8): 133-139. LIU Z W, LI Y H. Experimental investigation on the deformation and crack behavior of rock specimen with a hole undergoing uniaxial compressive load [J]. Engineering Mechanics, 2010, 27(8): 133-139.(in Chinese)
    [7] 王学滨, 杜亚志, 潘一山, 等. 大位移DIC方法及含孔洞砂土试样拉伸局部化带宽度观测[J]. 应用基础与工程科学学报, 2013, 21(5): 908-917. WANG X B, DU Y Z, PAN Y S, et al. A digital image correlation method for large displacement and measurements of the localized tensile strain band width of a sand specimen with a hole [J]. Journal of Basic Science and Engineering, 2013, 21(5): 908-917.(in Chinese)
    [8] 潘兵, 谢惠民. 数字图像相关中基于位移场局部最小二乘拟合的全场应变测量[J]. 光学学报, 2007, 27(11): 1980-1986. PAN B, XIE H M. Full-field strain measurement based on least-square fitting of local displacement for digital image correlation method [J]. Acta Optica Sinica, 2007, 27(11): 1980-1986.(in Chinese)
    [9] ZHOU P, GOODSON K E. Subpixel displacement and deformation gradient measurement using digital image/speckle correlation [J]. Optical Engineering, 2001, 40(8): 1613-1620.
    [10] BRUCK H A, MCNEILL S R, SUTTON M A, et al. Digital image correlation using Newton-Raphson method of partial differential correction [J]. Experimental Mechanics, 1989, 29(3): 261-267.
    [11] 王学滨, 张楠, 潘一山, 等. 单轴压缩湿土样最大剪切应变场数字图像相关方法结果的统计分析[J]. 岩土工程学报, 2016, 38(6): 996-1003. WANG X B, ZHANG N, PAN Y S, et al. Statistial analyses of maximum shear strain fields for wet soil specimens in uniaxial compression using digital image correlation method [J]. Chinese Journal of Geotechnical Engineering, 2016, 38(6): 996-1003.(in Chinese)
    引证文献
    网友评论
    网友评论
    分享到微博
    发 布
引用本文

王学滨,田锋,董伟,侯文腾,余斌.平面应变条件下含孔洞土样受内压作用的变形破坏过程[J].土木与环境工程学报(中英文),2019,41(6):27-35. Wang Xuebin, Tian Feng, Dong Wei, Hou Wenteng, Yu Bin. Experimental measurements of deformation and failure processes of plane strain clay specimens with holes and subjected to internal pressures[J]. JOURNAL OF CIVIL AND ENVIRONMENTAL ENGINEERING,2019,41(6):27-35.10.11835/j. issn.2096-6717.2019.111

复制
分享
文章指标
  • 点击次数:609
  • 下载次数: 838
  • HTML阅读次数: 478
  • 引用次数: 0
历史
  • 收稿日期:2019-04-30
  • 在线发布日期: 2019-12-12
文章二维码