土工基础

›› 2019, Vol. 33 ›› Issue (1): 75-77.

• 工程实录 • 上一篇    下一篇

洞庭湖砂纹淤泥质土动强度试验研究

李 懿1, 聂士诚2,付 钰3,杨 柏3   

  1. （1.广州市设计院，广州 510620;2.湖南省交通规划勘察设计院有限公司，长沙 410008；
    3.西南交通大学土木工程学院，成都 610031）
  • 收稿日期:2018-08-06 修回日期:2018-08-16 出版日期:2019-03-02 发布日期:2019-03-08
  • 作者简介:李 懿（1987-），男，博士,工程师，研究方向为岩土工程。
  • 基金资助:

    交通运输部企业技术创新类科技计划项目（2015315798060）；广西自然科学基金资助项目（2018GXNSFAA294020）

Experimental Study on the Dynamic Strength of Sandy GrainMucky Soil of Dongting Lake

LI Yi1, NIE Shicheng2, FU Yu3, YANG Bai3   

  1. （1.Guangzhou Design Institute, Guangzhou, Guangdong, 510620, China;
    2.Hunan Provincial Communications Planning, Survey & Design Institute Co.,Ltd. Changsha, Hunan, 410008;
    3.School of Civil Engineering, Southwest Jiaotong University, Chengdu，Sichuan, 610031, China）
  • Received:2018-08-06 Revised:2018-08-16 Online:2019-03-02 Published:2019-03-08

摘要： 砂纹淤泥质土是夹有微薄层粉细砂洞庭湖湖相沉积软土，具有独特薄砂层构造。为了研究砂纹淤泥质土动强度特性，通过确定洞庭湖砂纹淤泥质土动强度的破坏标准，以DDS-70动三轴试验系统为试验手段，探讨了围压、振动频率对洞庭湖砂纹淤泥质土动强度特性的影响。研究表明：（1）动粘聚力和动内摩擦角随循环次数的增加总体上呈下降趋势；（2）循环次数较小时动强度下降较快，而当循环周次超过一定次数时，动强度进入缓慢衰减阶段；（3）相同的循环次数下频率和围压越高，动粘聚力和动内摩擦角越大。

关键词: 砂纹淤泥质土, 动三轴试验, 围压, 频率, 动强度

Abstract: The sandy grainmucky soil is a special structured lacustrine deposited soil with fine sand lenses from Dongting Lake. The dynamic strength envelope of Dongting sandy grainmucky soi samples was experimental studied by using DDS70 dynamic triaxial testing device. The effect of confining pressure and applied cyclic axial frequency on the dynamic strength was evaluated. Throughout the investigation, the following conclusions are obtained: 1) The dynamic cohesion and dynamic internal friction angle values decrease the number of cyclic stress; 2) The sample strength decreases rapidly at the small number of cyclic stress and after the cyclic stress number reaches a certain value, dynamic strength decrease slowly with the increase of number of cycles; 3) under the same cyclic number, the higher the frequency and the confining pressure, the higher the dynamic cohesion and the dynamic internal friction angle.

Key words: sandy grainmucky soil, dynamic triaxial shear tests, confining pressure, frequency, dynamic strength