力学与实践 ›› 2018, Vol. 40 ›› Issue (6): 653-660.DOI: 10.6052/1000-0879-18-107

• 应用研究 • 上一篇    下一篇

冻结黏土力学特性分析及改进S-M蠕变模型1)

郭梦圆*,2), 姚兆明*,3), 李梦洁, 陈军浩**   

  1. *安徽理工大学土木建筑学院,安徽淮南 232001;
    淮南职业技术学院工程管理系,安徽淮南 232001;
    **福建工程学院土木工程学院,福州 350118
  • 收稿日期:2018-03-20 出版日期:2018-12-15 发布日期:2019-01-02
  • 作者简介:2) 郭梦圆,在读硕士生,主要从事土体本构理论和岩土数值分析研究。 E-mail: gmy229@163.com
  • 基金资助:
    国家自然科学基金项目(51504070)、 安徽省质量工程项目(2016jyxm0274)和福州市科技计划项目(2017-G-59)资助

ANALYSIS OF MECHANICAL CHARACTERISTICS OF FROZEN CLAY AND MODIFIED S-M CREEP MODEL1)

GUO Mengyuan*,2), YAO Zhaoming*,3), LI Mengjie, CHEN Junhao**   

  1. *College of Civil Engineering, Anhui University of Science and Technology, Huainan 232001, Anhui, China;
    Department of Engineering Management, Huainan Vocational Technical College, Huainan 232001, Anhui, China;
    **College of Civil Engineering, Fujian University of Technology, Fuzhou 350118, China
  • Received:2018-03-20 Online:2018-12-15 Published:2019-01-02
  • Contact: 姚兆明,教授,博士(后),主要从事土体本构理论和岩土数值分析研究。 E-mail: zhmyaoaust@126.com

摘要: 为合理描述人工冻结法施工的矿井土层力学特性,对某矿井土样的重塑土进行单轴抗压强度实验和单轴压缩蠕变实验,得到重塑冻结黏土在不同温度及载荷加载等级下的应力-应变曲线和蠕变曲线。实验结果表明:冻结温度越低,土样的单轴强度越大;相同冻结温度下,土样的蠕变变形随着应力水平的升高而增大。单轴压缩蠕变的等时应力-应变曲线随时间发展向应变轴靠拢;土样经历初始蠕变和等速蠕变两个阶段,在较高应力水平下有进入加速蠕变的趋势;对S-M模型中各参数的意义进行修正并考虑温度的影响,得到人工冻结黏土改进S-M蠕变显式模型,然后采用粒子群算法对人工冻结黏土S-M蠕变模型参数进行优化。改进S-M蠕变显式模型理论计算值与实验值吻合良好,表明改进S-M蠕变显式模型能较好模拟人工冻结黏土的蠕变特性。改进S-M蠕变显式模型为人工冻土蠕变计算提供一种新方法。

关键词: 重塑冻结黏土|蠕变变形|S-M蠕变显式模型|粒子群算法

Abstract: To describe the mechanical characteristics of the mine soil layer constructed by the artificial freezing method, the uniaxial compressive strength test and the uniaxial compression creep test are carried out by using the remolded soil samples of a certain mine, and the stress-strain curves and the creep curves of the remolded frozen clay at different temperatures and loading grades are obtained. Experimental results show that the uniaxial strength of the soil is higher at a lower frozen temperature; The creep deformation of the soil increases with the increase of the stress level at the same frozen temperature; The isochronous stress-strain curve of the uniaxial compression creep deviates with respect to the strain axis with time. The soil sample experiences two stages of the initial creep and the stable creep, with a tendency to enter the accelerated creep stage in a higher stress level. By modifying the meaning of the parameters in the Singh-Mitchell model and with consideration of the influence of temperature, the improved S-M creep explicit model of the artificial frozen clay is obtained. Then the parameters of the S-M creep explicit model are optimized by using the particle swarm algorithm. Compared with the modified S-M explicit model, the calculated values are in good agreement with the experimental data, which indicates that the modified S-M creep explicit model can well simulate the creep characteristics of the deep frozen clay. The modified S-M creep explicit model provides a new method for the creep calculation of the artificial frozen soil.

Key words: remolded frozen clay|creep deformation|S-M creep explicit model|particle swarm optimization

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