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冰川冻土 ›› 2016, Vol. 38 ›› Issue (4): 1052-1058.doi: 10.7522/j.issn.1000-0240.2016.0122

• 特殊土的力学特性与工程问题 • 上一篇    下一篇

冻融循环条件下层理砂岩卸荷力学特性试验研究

王乐华1, 姜照容2, 李建林1, 汤开宇1, 金晶1   

  1. 1. 三峡大学 三峡库区地质灾害教育部重点实验室, 湖北 宜昌 443002;
    2. 广东省地质局 第一地质大队, 广东 珠海 519000
  • 收稿日期:2016-02-05 修回日期:2016-07-12 出版日期:2016-08-25 发布日期:2016-09-19
  • 作者简介:王乐华(1977-),男,安徽怀宁人,教授,2007年在武汉大学获博士学位,现从事岩土工程方面的教学与科研.E-mail:lehuatg@126.com
  • 基金资助:
    国家自然科学基金项目(50909052;51439003);教育部重点项目(212114);水利部公益性行业科研专项(201401029)资助

The bedding sandstone unloading mechanical properties experimental study in the freeze-thaw cycle conditions

WANG Lehua1, JIANG Zhaorong2, LI Jianlin1, TANG Kaiyu1, JIN Jing1   

  1. 1. Key Laboratory of Geological Hazards on Three Gorges Reservoir Area, Ministry of Education, China Three Gorges University, Yichang 443002, Hubei, China;
    2. The First Geological Brigade of Guangdong Provincial Geology Authority, Zhuhai 519000, Guangdong, China
  • Received:2016-02-05 Revised:2016-07-12 Online:2016-08-25 Published:2016-09-19

摘要: 研究层理砂岩在两种含水状态(自由饱水与真空饱水)、不同冻融循环次数(0次、20次、40次、80次、120次)条件下的三轴卸荷力学特性.研究表明:砂岩的强度随着冻融循环次数的增加而降低,真空饱水组的劣化程度较自由饱水组剧烈,外观损伤破坏主要出现在岩样端部边缘和层理面附近.加载与残余变形阶段产生轴向应变;卸荷阶段,围压降低与变形增长具有良好的相关性,随着冻融次数增加,卸荷阶段应变量减少,冻融作用对卸荷效应更敏感.冻融次数对破坏模式的影响有一定规律但不显著,试样破坏以剪切破坏为主,但随着冻融次数的增加,张拉破坏有增强的趋势.

关键词: 冻融卸荷, 含水状态, 冻融循环, 偏应力, 层理岩体

Abstract: It studies the triaxial unloading mechanical properties of bedding sandstone under two kinds of moisture contents including free water-saturation and vacuum saturation and different freeze-thaw cycle times from 0 to 120 times). It shows that the strength of the sandstone decreases with the increase of freeze-thaw cycle times, and the degree of degradation of vacuum saturation group is more radical than that of free water-saturation group. Appearance damage occurs mainly in the edge of the rock's end and the vicinity of the bedding plane. The axial strain is produced in the stage of loading and residual deformation; and it has good correlation between the reduce of confining pressure and the growth of deformation in the unloading stage. The strain produced in the unloading stage is reduced with the increase of the freeze-thaw times, and unloading effect under the action of freeze-thaw becomes more sensitive. There are certain rules, but no significant, of the effect of the freeze-thaw times to failure mode, and sample destructions are mainly shear failure, but the tensile failure has a tendency to increase with the increase of freeze-thaw times.

Key words: freeze-thaw unloading, moisture contents, freeze-thaw cycle, deviation stress, bedding rock mass

中图分类号: 

  • TD313