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冰川冻土 ›› 2016, Vol. 38 ›› Issue (2): 409-415.doi: 10.7522/j.issn.1000-0240.2016.0045

• 寒区科学与技术 • 上一篇    下一篇

青藏粉土单向冻结冻胀率变化特性研究

王永涛1 2, 王大雁1, 郭妍1 2, 雷乐乐1 2, 顾同欣1   

  1. 1. 中国科学院 寒区旱区环境与工程研究所 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
  • 收稿日期:2015-11-17 修回日期:2016-01-23 出版日期:2016-04-25 发布日期:2016-07-13
  • 通讯作者: 王大雁,E-mail:dywang@lzb.ac.cn E-mail:dywang@lzb.ac.cn
  • 作者简介:王永涛(1989-),男,甘肃庆城人,2011年毕业于中国矿业大学(徐州),现为中国科学院寒区旱区环境与工程研究所在读博士研究生,主要从事冻土物理力学方面的研究.E-mail:wangyongtao@lzb.ac.cn
  • 基金资助:
    国家自然科学基金项目(41071048);冻土工程国家重点实验室基金项目(SKLFSE-ZT-17);国家重点基础研究发展计划(973计划)项目(2012CB026106)资助

Experimental study of the development characteristic of frost heaving ratio of the saturated Tibetan silt under one-dimensional freezing

WANG Yongtao1 2, WANG Dayan1, GUO Yan1 2, LEI Lele1 2, GU Tongxin1   

  1. 1. State Key Laboratory of Frozen Soils Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-11-17 Revised:2016-01-23 Online:2016-04-25 Published:2016-07-13

摘要: 开展了饱和青藏粉土在开放系统不同温度梯度条件下的单向冻结试验,对冻结过程中冻结深度和冻胀速率的发展变化过程进行了研究.结果表明:不同顶板温度下,土样均在25 h左右达到冻结稳定状态,之后冻结深度基本不再发生变化.土样冻结过程中,冻胀速率表现为快速减小、较小值保持稳定、快速增大、较大值保持稳定四个阶段.基于以上试验结果,对土样冻结过程中冻胀率的变化过程进行了研究,发现冻胀率随冻结深度的增加先减小后增加,冻胀率从减小变为增大的时刻就是冻结深度趋于稳定的时刻,而冻胀率快速增大的时刻为冻胀速率进入较大值保持阶段的时刻.冻胀率变化的内在机理为土样冻结过程中由冰透镜体分凝所导致的未冻区固结和已冻区冻胀共同作用的结果.

关键词: 单向冻结, 冻结深度, 冻胀速率, 冻胀率, 冰分凝

Abstract: Based on one-dimensional freezing test under five different cooling temperature gradients in an open system, the frozen depth and frost heaving ratio of the saturated Tibetan silt are studied experimentally. Some conclusions are showed as following. Firstly, although the top cooling temperatures are different, but the freezing front in sample reaches stability near 25 hours. In the freezing process, the frost heaving rate undergoes four stages, which are rapid decrease stage, stable stage, rapid increase stage and another stable stage. The frost heaving ratio is related to the development of the frozen depth and the frost heaving rate. The frost heaving ratio become to increase when the frozen depth tends to stable. The last stable stage of frost heaving rate contributes mostly to the increasing of frost heaving ratio. The mechanics of the development of the frost heaving ratio is induced by the combined effect of the unfrozen part consolidation and frozen part frost heave of soil sample.

Key words: one-dimensional freezing, frozen depth, frost heaving rate, frost heaving ratio, ice lens segregation

中图分类号: 

  • P642.14