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力学与实践 ›› 2018, Vol. 40 ›› Issue (2): 155-160.doi: 10.6052/1000-0879-17-367

• 应用研究 • 上一篇    下一篇

基于Hansbo渗流的圆柱土样Biot固结分析1)

刘忠玉2), 朱新牧, 夏洋洋, 郑占垒, 张家超   

  1. 郑州大学土木工程学院, 郑州 450001;
  • 收稿日期:2017-10-27 修回日期:2017-11-15 出版日期:2018-04-15 发布日期:2018-05-18
  • 通讯作者: 2) 刘忠玉,教授,主要从事岩土力学等方面的教学和科研工作. E-mail:zhyliu@zzu.edu.cn
  • 基金资助:

    1) 国家自然科学基金资助项目(51578511).

BIOT’S CONSOLIDATION ANALYSIS FOR CYLINDRICAL SOIL-SAMPLE BASED ON HANSBO’S FLOW1)

LIU Zhongyu2), ZHU Xinmu, XIA Yangyang, ZHENG Zhanlei, ZHANG Jiachao   

  1. School of Civil Engineering, Zhengzhou University, Zhengzhou 450001, China;
  • Received:2017-10-27 Revised:2017-11-15 Online:2018-04-15 Published:2018-05-18

摘要:

诸多黏性土渗流试验表明,在低水力梯度下渗流会出现明显偏离Darcy定律的现象. 为了分析渗流的非Darcy特性对固结过程 的影响,引入Hansbo渗流方程描述圆柱土样内的渗流,重新推导轴对称条件下的Biot固结方程,并给出方程的Crank--Nicolson有限 差分格式. 通过与Darcy渗流条件下轴对称Biot固结方程解析解的对比,验证计算方法的有效性. 然后分析Hansbo模型参数对圆柱 土样固结过程的影响. 计算结果表明:与Darcy渗流相比,Hansbo渗流会延缓圆柱土样的固结过程. 随着Hansbo渗流参数m或I1的增大,在固结前期,Mandel--Cryer效应会更加显著,即孔隙水压力峰值将提高,且达到该峰值的时间 会延迟;在固结中后期,孔压消散滞后的现象也更加明显. 不过,Hansbo渗流对位移的影响很小.

关键词:

Biot固结|Hansbo渗流|有限差分|Mandel-Cryer效应|固结度

Abstract:

Some clay permeability tests show that the flow of the pore water in clays may depart from the Darcy law under the condition of the lower hydraulic gradient. In order to investigate the influence of the non-Darcy behavior of flow on the consolidation process, the Hansbo equation is introduced to describe the flow in cylindrical soil samples and the Biot consolidation equation under axisymmetric conditions is modified. The numerical analysis is performed by using the Crank--Nicolson finite difference method. The proposed method is validated by comparing the analytical solution of the axisymmetric Biot’s consolidation equation with the Darcy flow. Then the influence of the Hansbo’s flow parameters on the consolidation process of the cylindrical soil sample is investigated. The numerical results show that the Hansbo’s flow delays the consolidation process of the saturated clay compared with the Darcy flow. At the early stage of consolidation, the Mandel-Cryer effect becomes more significant with the increase of the Hansbo’s flow parameters. In other words, the peak value of the pore water pressure will increase, and the reaching of its peak will also be delayed. Similarly, the delaying phenomenon of the pore water pressure dissipation is also more obvious in the later stage of consolidation. However, the Hansbo’s flow has little effect on the displacement in the cylindrical soil.

Key words:

Biot's consolidation|Hansbo's flow|finite difference|Mandel-Cryer effect|degree of consolidation

中图分类号: 

  • TU433