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冰川冻土 ›› 2018, Vol. 40 ›› Issue (1): 62-69.doi: 10.7522/j.issn.1000-0240.2018.0008

• 寒区科学与技术 • 上一篇    下一篇

冻融循环对青藏红黏土物理力学性质影响试验研究

房建宏1, 陈鑫2,3, 徐安花1, 张泽2   

  1. 1. 青海省交通科学研究院, 青海 西宁 810001;
    2. 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;
    3. 中国科学院大学, 北京 100049
  • 收稿日期:2017-12-26 修回日期:2018-02-23 出版日期:2018-02-25 发布日期:2018-04-13
  • 通讯作者: 张泽,E-mail:zhangze@lzb.ac.cn E-mail:zhangze@lzb.ac.cn
  • 作者简介:房建宏(1967-),男,陕西临潼人,研究员,2017年在北京交通大学获博士学位,从事冻土、盐渍土地区公路病害防治研究.E-mail:13709719909@163.com
  • 基金资助:
    青海省交通科学研究院开放基金项目(2016-01-04);国家自然科学基金项目(41771078;41771074);冻土工程国家重点实验室自主研究项目(SKLFSE-ZT-19)资助

Experimental study of the influence of freezing-thawing cycles on physical and mechanical properties of Qinghai-Tibet red clay

FANG Jianhong1, CHEN Xin2,3, XU Anhua1, ZHANG Ze2   

  1. 1. Qinghai Research Institute of Transportation, Xining 810001, China;
    2. State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-12-26 Revised:2018-02-23 Online:2018-02-25 Published:2018-04-13

摘要: 以红黏土为研究对象,使土样在封闭系统下进行不同次数的冻融循环作用,对冻融循环后的冻结土样进行粒度成分和物理力学性质测试,研究不同次数冻融循环作用下冻结红黏土粒度成分和物理力学性质的变化规律。结果表明:粉粒组和黏粒组质量含量受冻融循环作用次数影响较大。红黏土中颗粒在前10次冻融循环过程中向粒径小于0.001 mm及粒径在0.01~0.05 mm范围富集;冻融循环10次之后,随冻融循环次数的增加,粒径范围在0.002~0.005 mm的土颗粒含量明显增加,粒径范围在0.01~0.05 mm的土颗粒含量明显减小,其他粒径范围的土颗粒含量基本不受冻融循环次数的影响。红黏土的液、塑限大体上随冻融循环次数的增加而增加。冻融循环作用对红黏土等效黏聚力强度影响较明显,冻融循环作用10次以内红黏土等效黏聚力强度变化较大,在红黏土地区新修路基应考虑冻融循环作用引起的附加沉降影响。建议采用维亚洛夫或吴紫汪长期强度预报方程预测红黏土长期等效黏聚力强度。

关键词: 青藏红黏土, 冻融循环, 物理性质, 球形模板压入仪, 等效黏聚力

Abstract: Red clay was taken as research object, specimens from which had gone through different numbers of freezing-thawing cycles within a closed system. The changes of particle size composition and physical-mechanical properties of red clay under different freezing-thawing cycles were studied. The results showed that the specimens of powder group and clay group were significantly affected by the number of freezing-thawing cycles. The specimens with red clay particle size of less than 0.001 mm and particle size in the range of 0.01-0.05 mm had enriched in the first 10 cycles. After 10 cycles of freezing-thawing, the content of soil particles with particle size range from 0.002 mm to 0.005 mm had increased obviously with the increase of the cycles, and the content of soil particles with particle size range from 0.01 mm to 0.05 mm had decreased obviously. Soil particle content in the other particle size range had not affected by the number of the cycles nearly. The liquid and plastic limits of the red clay had increased with the increase of the number of the cycles. The effect of freezing-thawing cycles on the equivalent cohesive strength of red clay was more obvious. The effect of freezing-thawing cycles on the equivalent cohesive strength of red clay had varied greatly within the first 10 cycles. The new roadbed with red clay should consider the effect of additional settlement caused by freezing-thawing cycles. It is suggested that the long-term equivalent cohesive strength of red clay should predict by equation of Vyalov or Wu.

Key words: Qinghai-Tibet red clay, freezing-thawing cycles, physical properties, spherical template indenter, equivalent cohesion

中图分类号: 

  • TU43