膨润土对CSM墙体强度和渗透特性的影响
DOI:
作者:
作者单位:

1.东南大学;2.南京城建隧桥经营管理有限责任公司

作者简介:

通讯作者:

中图分类号:

TU525.9

基金项目:

国家重点基础研究发展计划(973计划)复杂荷载环境下滨海软弱土损伤机制与测试、评价体系


Influence of bentonite on the UCS and hydraulic characteristicsof CSM Wall
Author:
Affiliation:

1.School of Transportation, Southeast University;2.Nanjing City Construction Tunnel Bridge Management

Fund Project:

Damage mechanism and testing and evaluation system of coastal soft soil under complex load environment

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    膨润土浆液常作为地下工程双轮铣水泥土搅拌墙(CSM)的铣削液来改善土体搅拌均匀性能和维持槽壁稳定。通过室内试验研究膨润土-水泥土试样无侧限抗压强度和渗透系数等特性随膨润土掺入量的变化情况,并结合压汞试验分析掺入膨润土对水泥土微观孔隙特征的影响。探讨掺入膨润土后试样孔隙比的变化与水泥土试样无侧限抗压强度和渗透系数的关系,并量化试样孔隙变化过程。结果表明,掺入膨润土可使渗透系数降低两个数量级和显著提高无侧限抗压强度;无侧限抗压强度和孔隙比、水泥掺量的比值近似呈幂函数关系;膨润土自身的膨胀性、分散性和亲水性可以有效填充孔隙,同时与水泥水化产物发生化学反应,改变水泥土孔隙分布;一定量的膨润土掺入量对改善水泥土试样承强防渗效果显著,但一味增加膨润土掺量改善的边际效果不明显,在固化粉土和砂土试样中膨润土的最佳掺入量分别为5%和2.5~5%。

    Abstract:

    Soil-Bentonite Mixtures is often used to maintain the stability of the Deep Mixed Pile Method for the Double Round Milling Wall(Cutter Soil Mixing, CSM). The effect of bentonite content on the unconfined compressive strength and permeability of soil-bentonite mixtures in CSM when the local soil was sand and silt. The properties including the unconfined compressive strength and permeability was measured, and microstructure was investigated using MIP. The relationship between the change of pore ratio and the unconfined compressive strength and permeability coefficient of cement soil samples was investigated, and the pore change process of the sample was quantified. The results show that the expansion of the bentonite and chemical reaction with cement hydration products can change the pore distribution of soil-bentonite mixtures; The variation of bentonite content can reduce the permeability coefficient by two orders of magnitude and significantly improve the unconfined compressive strength; The ratio of compressive strength to porosity and cement content is approximately a power function relationship; A certain amount of bentonite is effective in improving the strength of the cement soil sample, but the marginal effect of improving the dosage is not obvious. The optimum content of bentonite in silt is 5% and in sand is 2.5~5%.

    参考文献
    相似文献
    引证文献
引用本文
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2019-12-12
  • 最后修改日期:2020-03-11
  • 录用日期:2020-04-07
  • 在线发布日期:
  • 出版日期: