岩土力学 ›› 2020, Vol. 41 ›› Issue (1): 32-38.doi: 10.16285/j.rsm.2018.2135

• 基础理论与实验研究 • 上一篇    下一篇

压实黏土三轴压缩变形过程中的渗透性变化规律

王刚1, 2,韦林邑3,魏星4,张建民5   

  1. 1. 重庆大学 山地城镇建设与新技术教育部重点实验室,重庆 400045;2. 重庆大学 库区环境地质灾害防治国家地方联合工程研究中心,重庆 400045;3. 重庆大学 土木工程学院,重庆 400045;4. 西南交通大学 土木工程学院,四川 成都 610031;5. 清华大学 土木水利学院,北京 100084
  • 收稿日期:2018-11-21 修回日期:2019-05-05 出版日期:2020-01-13 发布日期:2020-01-05
  • 作者简介:王刚,男,1978年生,博士,教授,主要从事土动力学、高坝大型结构和岩土工程数值分析方面的研究工作
  • 基金资助:
    国家自然科学基金(No.41602286,No.51679016);重庆市自然科学基金(No. cstc2018jcyjAX0752)

Permeability evolution of compacted clay during triaxial compression

WANG Gang1, 2, WEI Lin-yi3, WEI Xing4, ZHANG Jian-min5   

  1. 1. Key Laboratory of New Technology for Construction of Cities in Mountain Area, Chongqing University, Chongqing 400045, China; 2. National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas, Chongqing University, Chongqing 400045, China; 3. School of Civil Engineering, Chongqing University, Chongqing 400045, China; 4. School of Civil Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China; 5. School of Civil Engineering, Tsinghua University, Beijing 100084, China
  • Received:2018-11-21 Revised:2019-05-05 Online:2020-01-13 Published:2020-01-05
  • About author:First author: WANG Gang, male, (1978-), PhD, Professor, mainly engaged in research on soil dynamics, high dam and numerical analysis of geotechnical engineering. E-mail: cewanggang@163.com
  • Supported by:
    This work is supported by the National Natural Science Foundation of China (41602286, 51679016) and Chongqing Natural Science Foundation (cstc2018jcyjAX0752).

摘要: 对某高坝心墙黏土进行了三轴压缩过程中的轴向渗透试验,观测了不同压实密度的试样在不同围压下轴向渗透系数随轴向应变的变化过程以及试样的变形形态。试验发现,三轴压缩过程中试样的渗透系数的变化趋势与压实密度和围压有关。当围压大于试样的前期固结压力时,试样在三轴压缩过程中一直呈现体缩,变得更密实,因而渗透系数随着轴向应变的增加而减小,最后趋于稳定。当围压远小于试样的前期固结压力时,试样产生了对抗渗不利的集中剪切带,集中剪切带成为渗流通道,使得试样的表观轴向渗透系数随轴向应变的增加而显著增大。重度压实的黏土在低围压下的大剪切变形下会产生高渗漏性的集中剪切带的试验事实,可以用来解释土石坝心墙的局部渗漏现象。

关键词: 三轴渗透试验, 渗透系数, 应变局部化, 剪切渗透带

Abstract: Triaxial seepage tests were conducted on the core-wall clay of a high rock-fill dam to investigate the change of hydraulic conductivity with axial strain. It was found that the compaction density and confining pressure were the two main factors influencing the change of hydraulic conductivity during triaxial compression. When the current confining pressure was greater than the pre-consolidation pressure of a compacted specimen, the specimen kept being compressed and became denser during the compression process, resulting in a decreasing trend in its hydraulic conductivity until it eventually reached a stable state. On the other hand, if the current confining pressure was far less than the pre-consolidation pressure of the specimen, the specimen deformed in a localised shear band which weakened the impermeability of the specimen, and as the shear band continued to dilate, an increasing trend in the overall hydraulic conductivity was observed. This study highlighted an important fact that heavily compacted clay under low confining pressures had a high susceptibility to localised shear bands of high permeability, which could be used to explain many historical leakage problems observed in clay-core dams.

Key words: triaxial seepage test, hydraulic conductivity, strain localisation, shear-induced leakage band

中图分类号: 

  • TU 411
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