土水特征曲线预测非饱和黏土的抗剪强度

doi:10.3969/j.issn.1007-2861.2015.01.015

上海大学学报(自然科学版) ›› 2016, Vol. 22 ›› Issue (5): 648-655.doi: 10.3969/j.issn.1007-2861.2015.01.015

土水特征曲线预测非饱和黏土的抗剪强度

李万双, 孙德安, 高游

上海大学土木工程系, 上海 200072

收稿日期:2015-01-29 出版日期:2016-10-31 发布日期:2016-10-31
通讯作者: 孙德安(1962—), 男, 教授, 博士生导师, 博士, 研究方向为非饱和土力学. E-mail: sundean@shu.edu.cn
作者简介:孙德安(1962—), 男, 教授, 博士生导师, 博士, 研究方向为非饱和土力学. E-mail: sundean@shu.edu.cn
基金资助:
国家自然科学基金资助项目(11272194)

Predicting shear strength of unsaturated clay using soil-water characteristic curve

LI Wanshuang, SUN Dean, GAO You

Department of Civil Engineering, Shanghai University, Shanghai 200072, China

Received:2015-01-29 Online:2016-10-31 Published:2016-10-31

摘要/Abstract

摘要：

分别采用压力板法和滤纸法对一种孔隙比大致相同的黏土进行了测量土水特征曲线的试验, 并通过直剪仪试验测得不同含水率下该黏土的抗剪强度(简称强度). 试验结果表明: 压力板法和滤纸法测得的土水特征曲线大致相同; 同样竖向压力下, 抗剪强度随饱和度降低而增大, 但饱和度很低时强度反而减小. 饱和度主要影响黏聚力, 对内摩擦角的影响不大. 另外, 应用土水特征曲线对非饱和黏土的强度进行了预测. 通过引入有效饱和度的概念, 对非饱和土强度公式进行修正, 采用该公式预测非饱和土强度的精度比传统的平均骨架应力预测方法要高.

关键词: 抗剪强度, 滤纸法 , 土水特征曲线 , 压力板法

Abstract:

The pressure plate method and filter paper method were used to measure the soil-water characteristic curve (SWCC) of clay with almost the same initial void ratio. Shear strength were obtained by performing a series of direct shear tests on the clay under different unsaturated conditions. SWCCs of the silty clay obtained with the pressure plate and filter paper methods were nearly the same. With the same pressure, shear strength increased with a decreasing degree of saturation, and decreases at a very low degree of saturation. The degree of saturation had great influence on cohesion and little influence on the internal friction angle. Shear strength of unsaturated clay was predicted using SWCC. To precisely predict shear strength, a concept of effective degree of saturation was introduced to modify the traditional strength formula of unsaturated clay. The modified formula could better predict tested data.

Key words: filter paper method , shear strength, soil-water characteristic curve(SWCC) , pressure plate method

李万双, 孙德安, 高游. 土水特征曲线预测非饱和黏土的抗剪强度[J]. 上海大学学报(自然科学版), 2016, 22(5): 648-655.

LI Wanshuang, SUN Dean, GAO You. Predicting shear strength of unsaturated clay using soil-water characteristic curve[J]. Journal of Shanghai University（Natural Science Edition）, 2016, 22(5): 648-655.

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土水特征曲线预测非饱和黏土的抗剪强度

Predicting shear strength of unsaturated clay using soil-water characteristic curve

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