土工基础 ›› 2020, Vol. 34 ›› Issue (2): 190-193.

• 专题论述 • 上一篇    下一篇

不同饱和度下黏粒含量对土体强度特性的影响

池秋慧,董金玉   

  1. (华北水利水电大学,郑州 450045)
  • 收稿日期:2019-08-05 修回日期:2019-09-24 出版日期:2020-05-20 发布日期:2020-05-20
  • 通讯作者: 董金玉(1977-),男,教授,博导,博士,研究方向为地质工程。
  • 作者简介:池秋慧(1991-),女,硕士研究生,研究方向为地质工程。

Influence of Clay Contents on Soil Strength Property under Different Degrees of Saturation

CHI Qiuhui, DONG Jinyu   

  1. (North China University of Water Resources and Electric Power, Zhengzhou 450045)
  • Received:2019-08-05 Revised:2019-09-24 Online:2020-05-20 Published:2020-05-20

摘要: 通过对山东东明某风电场细粒土进行不同饱和度、不同黏粒含量的直剪试验,研究了土体剪应力剪切位移关系及抗剪强度的变化规律。结果表明:细粒土在低饱和度下的剪应力剪切位移关系呈应变软化,脆性破坏;高饱和度下呈应变硬化,塑性破坏;且土体内黏粒含量越多,剪应力剪切位移曲线的应变软化行为越弱,应变硬化现象发生得越早;粉土随着饱和度的增加,抗剪强度持续下降无峰值,明显受黏聚力影响;粉质黏土和黏土随饱和度的增加,抗剪强度表现出先升后降的特点,受内摩擦角影响加大;细粒土中黏粒含量不同,土体抗剪强度受饱和度影响的程度和形式便不同。

关键词: 细粒土, 饱和度, 黏粒含量, 剪应力-剪切位移关系, 抗剪强度

Abstract: In this paper, direct shear tests were performed to study the influence of various degrees of saturation and clay contents on the shear strength of soil samples collected from a wind farm in Shandong Province. The test results showed that the shear stress-shear displacement relationship under the condition of a low degree of saturation was strain softening, and the strain hardening under a high degree of saturation. In addition to this, the plasticity of the cohesive soil sample increases with the increase in clay contents. With the increase in the degree of saturation, the cohesive forces among soil particles decrease which results in the decrease in shear strength of silty soil samples. Further, with the increase in clay contents, the shear strength of silty soil samples at first increases and then decreases, which is affected by the angle of internal friction. Overall, the clay content is an important factor that controls the effect of degree of saturation on the shear strength of finegrained soils.

Key words: fine-grained soils, degree of saturation, clay content, shear stress-shear displacement relationship, shear strength

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