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冰川冻土 ›› 2021, Vol. 43 ›› Issue (2): 535-543.doi: 10.7522/j.issn.1000-0240.2020.0020

• 寒区工程与灾害 • 上一篇    下一篇

石灰改良红层无侧限抗压强度试验研究

周宇1,2(), 李国玉1,2,3(), 武红娟4, 穆彦虎1, 赵文斌5, 毛云程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.中国科学院 西北生态环境资源研究院 大兴安岭冻土工程与环境观测试验研究站, 黑龙江 加格达奇 165000
    4.西北民族大学, 甘肃 兰州 730030
    5.甘肃民航机场集团有限公司, 甘肃 兰州 730020
  • 收稿日期:2019-12-21 修回日期:2020-04-22 出版日期:2021-04-30 发布日期:2021-05-18
  • 通讯作者: 李国玉 E-mail:zhouyu@lzb.ac.cn;guoyuli@lzb.ac.cn
  • 作者简介:周宇,博士研究生,主要从事寒区岩土工程研究. E-mail: zhouyu@lzb.ac.cn
  • 基金资助:
    甘肃省交通运输厅科技项目(201600009);NSFC-新疆联合基金项目(U1703244);国家自然科学基金项目(41672310);甘肃省科技重大专项(143GKDA007);国家重点研发计划项目(2017YFC0405101)

Experimental study on the unconfined compressive strength of lime stabilized red-mudstone

Yu ZHOU1,2(), Guoyu LI1,2,3(), Hongjuan WU4, Yanhu MU1, Wenbin ZHAO5, Yuncheng MAO1   

  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.Da Xing’anling Observation and Research Station of Frozen-ground Engineering and Environment,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Jiagedaqi 165000,Heilongjiang,China
    4.Northwest Minzu University,Lanzhou 730030,China
    5.Gansu Civil Aviation Airport Group Co. ,Ltd. ,Lanzhou 730020,China
  • Received:2019-12-21 Revised:2020-04-22 Online:2021-04-30 Published:2021-05-18
  • Contact: Guoyu LI E-mail:zhouyu@lzb.ac.cn;guoyuli@lzb.ac.cn

摘要:

红层是一种特殊岩土,作为路基材料时,常会导致不均匀沉陷、翻浆冒泥等病害。为改善其力学性质,工程上通常掺入一定剂量的石灰(Ca(OH)2)进行改良。由于降水-蒸发的周期性变化,运营期间反复干湿循环作用对路基土的工程性质造成较大影响。基于此,结合室内无侧限抗压强度试验,研究了干湿循环作用对不同掺量的石灰改良红层无侧限抗压强度的影响。结果表明:在最佳含水率下,石灰改良红层的无侧限抗压强度随石灰掺量的增加而增大;干湿循环作用对改良红层无侧限抗压强度的影响与石灰掺量有关,石灰掺量较低时,改良红层的抗压强度随干湿循环次数的增加而减小,石灰掺量较高时,改良红层的无侧限抗压强度随干湿循环次数的增加而显著增大;未改良红层塑性较大,试样均为塑性鼓胀破坏,掺入石灰后,红层强度增大,脆性增强,呈脆性剪切破坏,经历干湿循环作用后,石灰改良红层试样呈多缝锥形破坏。

关键词: 红层, 干湿循环作用, 石灰改良红层, 无侧限抗压强度

Abstract:

Red-mudstone is a kind of special soil. When the weathering red-mudstone was used as the filling materials,lots of engineering problems appeared, such as the uneven settlement, the lower bearing capacity and shoulder of road gushing, etc. In order to improve its mechanical properties, a certain amount of lime (Ca(OH)2) is usually added in engineering. However, the cyclic drying and wetting during operation has a great influence on the engineering properties of roadbed soil due to periodic variation of rainfall and draught. A series of unconfined compression tests were conducted to study the influence of wetting-drying cycle on the unconfined compressive strength of the stabilized red-mudstone with different content of lime. The test results show that the unconfined compressive strength of the stabilized red-mudstone increases with the increase of the content of lime. The influence of wetting-drying cycle on the unconfined compressive strength of the stabilized red-mudstone is related to the content of lime. When the content of lime is low, the compressive strength of the stabilized soil decreases with the increase of the number of wetting-drying cycles. When the content of lime is high, the unconfined compressive strength of the stabilized soil increases significantly with the increase of the number of wetting-drying cycles. The destruction model of untreated red-mudstone specimens is plastic bulging failure. Due to the increase of soil strength and brittleness, the lime stabilized red-mudstone specimens show brittle shear failure. After the wetting-drying cycle, the destruction model of lime stabilized red-mudstone specimens is cone-shape failure.

Key words: red-mudstone, wetting-drying cycle, lime stabilized red-mudstone, unconfined compressive strength

中图分类号: 

  • TU446