X img

官方微信

img

群号:冰川冻土交流群

QQ群:218834310

高级检索
作者投稿 专家审稿 编辑办公 编委办公 主编办公

冰川冻土 ›› 2018, Vol. 40 ›› Issue (6): 1173-1180.doi: 10.7522/j.issn.1000-0240.2018.0411

• 寒区科学与技术 • 上一篇    下一篇

冻融循环作用下砂岩孔隙体积变形模型的建立与分析

李杰林, 刘汉文   

  1. 中南大学 资源与安全工程学院, 湖南 长沙 410083
  • 收稿日期:2018-03-05 修回日期:2018-05-09 出版日期:2018-12-25 发布日期:2019-01-21
  • 通讯作者: 刘汉文,E-mail:liuhanwen94@163.com E-mail:liuhanwen94@163.com
  • 作者简介:李杰林(1982-),男,湖南宁远人,副教授,2012年在中南大学获博士学位,从事采矿工程与寒区岩石力学研究.E-mail:lijielin@163.com
  • 基金资助:
    国家自然科学基金项目(41502327);国家重大科学仪器设备开发专项(2013YQ17046310);中南大学中央高校基本科研业务费专项资金项目(2017zzts795);中南大学贵重仪器设备开放共享基金(CSUZC201801)资助

Establishment and analysis of the volumetric deformation model of sandstone pores under the effect of freezing-thawing cycles

LI Jielin, LIU Hanwen   

  1. School of Resources and Safety Engineering, Central South University, Changsha 410083, China
  • Received:2018-03-05 Revised:2018-05-09 Online:2018-12-25 Published:2019-01-21

摘要: 为研究冻融作用下砂岩内部孔隙的扩展机制,基于弹性力学和热力学理论,建立了饱水孔隙内水结冰的体积变形计算模型。结合基于核磁共振技术的冻融循环作用下饱和砂岩的孔隙度变化和T2谱分布的试验结果,通过建立的孔隙体积变形计算模型,分析了冻融作用下砂岩的孔隙体积变形规律。结果表明:冻融作用下饱和砂岩的体积膨胀系数大于8.69%;单次冻融作用对砂岩试样的损伤较小,孔隙体积的变化范围在0.80%~1.03%之间;砂岩的孔隙收缩系数和孔隙弹性变形体积占比的变化规律一致,均为先增大后减小;砂岩试样的孔隙收缩系数在7.92%~8.04%之间,其孔隙弹性变形体积占比平均为97.79%;在冻融过程中大孔隙的弹性变形比小孔隙的弹性变形更小。

关键词: 冻融循环, 变形模型, 核磁共振, 弹性变形体积

Abstract: In this paper, the expansion mechanisms of pores in sandstone under freezing-thawing cycles were studied, and a volumetric deformation model of water frozen in the pores under saturated condition has been established based on the theory of elasticity and thermodynamics. By combining the change of porosity in the saturated sandstone and T2 spectrum distribution test results under the effect of freezing-thawing cycles by means of nuclear magnetic resonance, a volumetric deformation model has been established, thus the rule of pore volumetric deformation of sandstone due to freezing-thawing has been analyzed. The results show that the value of volume expansion coefficient of saturated sandstone under the effect of freezing-thawing cycles is more than 8.69%. The damage of once freezing-thawing to the sandstone sample is less, and the change of the pore volume is within the range of 0.80%-1.03%. It is found that the variation of the pore shrinkage coefficient and the proportion of the pore elastic deformation volume are consistent, both are increasing first and then decreasing. The pore shrinkage coefficient of sandstone is within the range of 7.92%-8.04%, and the average volume proportion of pore elastic deformation is 97.79%. In the process of freezing-thawing, the elastic deformation of large pores is less than that of small pores.

Key words: freezing-thawing cycles, deformation model, nuclear magnetic resonance (NMR), elastic deformation volume

中图分类号: 

  • TU458