长江科学院院报 ›› 2014, Vol. 31 ›› Issue (3): 77-83.DOI: 10.3969/j.issn.1001-5485.2014.03.012

• 试验研究 • 上一篇    下一篇

土-格栅界面强度参数和剪切刚度试验研究

张俊峰1a, 1b, 王协群1a, 2, 邹维列1a, 1b, 温家华3   

  1. 1. 武汉大学 a.岩土与结构工程安全湖北省重点实验室; b. 土木建筑工程学院, 武汉 430072;

    2.武汉理工大学 土木建筑工程学院, 武汉 430070;
    3. 国网新源建设有限公司, 北京 100053
  • 收稿日期:2013-11-18 修回日期:2014-03-07 出版日期:2014-03-07 发布日期:2014-03-07
  • 通讯作者: 王协群(1971-), 女, 江苏扬州人, 教授, 博士, 主要从事土工合成材料和非饱和土特性方面的教学与科研工作, (电话)18971496971(电子信箱)xqscwang@126.com。
  • 作者简介:张俊峰(1988-), 男, 湖北随州人, 博士研究生, 主要从事加筋土结构与非饱和土特性的研究工作, (电话)18986162768(电子信箱)zhangjfwhu@163.com。
  • 基金资助:
    国家自然科学基金资助项目(51109171); 岩土与结构工程安全湖北省重点实验室开放研究基金项目(HBKLCIV201209);国家留学基金委资助(留金发【2013】3018)

Experimental Study on Shear Strength Parameters and Shear Stiffness Behavior of Soil-Geogrid Interface

ZHANG Jun-feng1, 2, WANG Xie-qun1, 3, ZOU Wei-lie1, 2, WEN Jia-hua4   

  1. 1. Key Laboratory of Safety for Geotechnical and Structural Engineering of Hubei Province, Wuhan University, Wuhan 430072, China; 2. School of Civil Engineering, Wuhan University, Wuhan 430072, China; 3.School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, China; 4.State Grid Xinyuan Construction Co., Ltd., Beijing 100053, China
  • Received:2013-11-18 Revised:2014-03-07 Online:2014-03-07 Published:2014-03-07

摘要: 以4种不同土工格栅和2种不同填料为试验材料, 完成了不同填料初始状态(含水率、干密度)和不同剪切速率的筋-土界面特性直剪试验, 详细分析了不同工况对界面强度参数和剪切刚度的影响。结果表明:①填料压实度的增大和剪切速率的增大会分别引起格栅-砂砾石界面抗剪强度参数的增大;②格栅-砂砾石界面的抗剪强度参数和剪切刚度明显都大于格栅-黏土界面;③格栅-黏土界面似黏聚力和内摩擦角随着填料含水率的增大而显著降低, 而且格栅-黏土界面强度参数对含水率比黏土本身更为敏感;④现行规范中对格栅-土界面摩擦因数比的推荐值为0.8是合适的, 但是总结文献发现, 拉拔试验所得到的筋-土界面强度参数都远小于直剪试验;⑤法向压力的增加、填料压实度的增加、黏土填料含水率的减小以及剪切速率的减小都会使筋土界面剪切刚度明显增大;⑥在采用的4种格栅中, 纵肋较短的单向格栅-砂砾石界面的剪切刚度最大, 其余3种格栅的筋土界面剪切刚度比较接近。

关键词: 土工格栅, 填料, 界面强度, 剪切刚度

Abstract: Direct shear tests were conducted on soil-grid interfaces composed of 4 types of geogrids and 2 types of soils to investigate the characteristics of geogrid-soil interface. The influencing factors including the initial state of soils (water content and dry density) and shearing rate on the shearing strength parameters and shearing stiffness were examined. The results indicated that: (1) With regard to geogrid-sandy gravel interfaces, higher impaction degree or shearing rate resulted in larger shear strength. (2) Both the shear strength parameters and shear stiffness of geogrid-sandy gravel interface were significantly higher than those of geogrid-clay interface. (3) Both the cohesion and the internal friction angle of geogrid-clay interface decrease remarkably with the increase of water content. The strength of geogrid-clay interface is more sensitive to water content than clay itself. (4) The recommended value of friction factor ratio (0.8) in current codes is suitable. But according to literatures it was found that the shear strength of the interface obtained from pull-out test was much smaller than that from direct shear test. (5) All the factors including the increasing of vertical stress and degree of compaction, the decreasing of water content and shearing rate would result in the apparent increase of shear stiffness. (6) The shear stiffness of the interface between uniaxial geogrid with short longitudinal ribs and sandy gravel was the largest, and the other three geogrids showed similar interface shear stiffness.

Key words: geogrid, filling, interface shear strength, shear stiffness

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