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冰川冻土 ›› 2017, Vol. 39 ›› Issue (4): 842-849.doi: 10.7522/j.issn.1000-0240.2017.0094

• 寒区科学与技术 • 上一篇    下一篇

兰州九州重塑黄土的抗拉变形破坏机理

吴旭阳1,2,3, 梁庆国3, 牛富俊1, 李国玉1   

  1. 1. 中国科学院 西北生态环境资源研究院 冻土工程国家重点实验室, 甘肃 兰州 730000;
    2. 中国科学院大学, 北京 100049;
    3. 兰州交通大学 土木工程学院, 甘肃 兰州 730070
  • 收稿日期:2016-12-14 修回日期:2017-06-02 出版日期:2017-08-25 发布日期:2017-11-15
  • 通讯作者: 梁庆国,E-mail:lqg_39@163.com E-mail:lqg_39@163.com
  • 作者简介:吴旭阳(1987-),男,河南许昌人,2015年在兰州交通大学获硕士学位,现为中国科学院西北生态环境资源研究院在读博士研究生,从事黄土及黄土隧道工程研究.E-mail:879333911@qq.com
  • 基金资助:
    国家自然科学基金项目(41562013);国家科技支撑计划项目(2014BAG05B05);甘肃省科技重大专项计划项目(143GKDA007);兰州交通大学“百名青年优秀人才培养计划”基金资助

Deformation failure mechanism in tensile test on remolded loess from Jiuzhou, Lanzhou

WU Xuyang1,2,3, LIANG Qingguo3, NIU Fujun1, LI Guoyu1   

  1. 1. State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
  • Received:2016-12-14 Revised:2017-06-02 Online:2017-08-25 Published:2017-11-15

摘要: 通过对不同干密度及含水量的重塑黄土进行室内抗拉强度试验,探究轴向压裂法致使试样破坏的机理及一般规律。结果表明,黄土的抗拉变形破坏可分为4种类型:I类,高干密度低含水量(干密度大于1.65 g·cm-3,含水量小于15%),抗拉强度介于8~12 kPa;Ⅱ类,低干密度低含水量(干密度小于1.60 g·cm-3,含水量小于15%),抗拉强度介于4~8 kPa;Ⅲ类,高干密度高含水量(干密度大于1.65 g·cm-3,含水量大于17%),抗拉强度介于4~8 kPa;IV类,低干密度高含水量(干密度小于1.60 g·cm-3,含水量大于17%),抗拉强度介于3~4 kPa。I类、Ⅱ类破坏类型属于脆性破坏,Ⅲ类、IV类属于塑性破坏。重塑黄土抵抗变形最弱的含水量为15%。通过对比分析黄土、普通黄黏土、红黏土及膨胀土的抗拉强度发现,在最优含水量处,不同干密度下黄土的抗拉强度均最小。黏性土的持水能力远超过黄土。黏土及膨胀土的抗拉强度均在最优含水量处达到最大值,而黄土的抗拉强度随着含水量的增加持续减小。研究结果对黄土强度特性的理解具有一定的参考意义。

关键词: 重塑黄土, 抗拉强度, 机理, 变形破坏

Abstract: The failure characteristics and patterns of loess under unconfined compress were studied on the remolded loess with different dry densities and water contents. The results indicated that the tensile failure of loess can be classified into four types:Type I with high density and low water content (dry density more than 1.65 g·cm-3 and water content less than 15%), with tensile strength between 8 and 12 kPa; Type Ⅱ with low density and low water content (dry density less than 1.60 g·cm-3 and water content less than 15%), with tensile strength between 4 and 8 kPa; Type Ⅲ with high density and high water content (dry density more than 1.65 g·cm-3 and water content more than 17%), with tensile strength between 4 and 8 kPa; Type IV with low density and high water content (dry density less than 1.60 g·cm-3 and water content more than 17%), with tensile strength between 3 and 4 kPa. Among the four types, Type I and Type Ⅱ had brittle failure, and Type Ⅲ and Type IV had plastic failure. The remolded loess exhibited the weakest resistance to deformation at water content of 15%. Compared with the tensile strengths of yellow clay, red clay and expansive soil under the condition of optimum water content and the same dry density, loess has the minimum tensile strength. In addition, the water holding capacity of clay was much more than that of loess. This research would be helpful to understand strength characteristics of loess.

Key words: remolded loess, tensile strength, mechanism, deformation failure

中图分类号: 

  • P642.11+6