雷胜友, 袁文治, 翟志刚,等.盐溶液质量分数对非饱和膨胀土抗剪强度的影响[J].河南理工大学学报（自然科学版）,2022,41(2):178-184.

LEI S Y, YUAN W Z, ZHAI Z G, et al. Effect of salt solution concentrations on shear strength of unsaturated expansive soil[J].Journal of Henan Polytechnic University(Natural Science) ,2022,41(2):178-184.

盐溶液质量分数对非饱和膨胀土抗剪强度的影响

雷胜友, 袁文治, 翟志刚, 田刚, 陈雨菲, 李思雨, 芦地, 柳明宇

长安大学 公路学院,陕西 西安 710064

摘要:为了探究盐溶液质量分数对非饱和膨胀土抗剪强度的影响,在传统Fredlund非饱和土抗剪强度公式的基础上,将基质吸力简化为常数,并引入渗透压力参数,提出盐溶液介入条件下 非饱和膨胀土的抗剪强度表达式。对4种质量分数的NaCl,KCl溶液改性膨胀土进行室内直剪试验,得到剪应力-应变曲线、抗剪强度线和黏聚力变化曲线。试验结果表明,盐溶液改性土的抗剪强度总体上低于素膨胀土的,提出的盐溶液介入条件下的抗剪强度表达式拟合度较高, 可以很好地反映受盐溶液影响的非饱和膨胀土的抗剪强度。通过改变双电层的厚度、土颗粒 间接触方式和结构特性,可研究盐溶液对非饱和膨胀土抗剪强度及黏聚力的影响,最后进一步探讨了非饱和膨胀土在盐溶液介入条件下剪切作用的微观机理。

关键词:非饱和膨胀土;盐溶液;直剪试验;抗剪强度

doi:10.16186/j.cnki.1673-9787.2020060023

基金项目:铁道部科技研究开发项目(2010G003-F)；地质灾害防治与地质环境保护国家重点实验室开放基金资助项目(GZ2005-03)；国家级大学生创新创业训练计划项目(201810710010；201910710172)；陕西省大学生创新创业训练计划项目 (S201910710035；S201910710025)

收稿日期:2020/06/09

修回日期:2020/09/24

出版日期:2022/03/15

Effect of salt solution concentrations on shear strength of unsaturated expansive soil

LEI Shengyou, YUAN Wenzhi, ZHAI Zhigang, TIAN Gang, CHEN Yufei, LI Siyu, LU Di, LIU Mingyu

School of Highway, Chandan University,Xi'an 710064 , Shaanxi, China

Abstract: In order to explore the effect of salt solution concentration on the shear strength of unsaturated expansive soil,based on the traditional Fredlund's unsaturated soil shear strength formula,the matrix suction was simplified to a constant,the osmotic pressure was introduced,and then the shear strength formula of unsaturated expansive soil under the intervention of salt solution was proposed.Furthermore,indoor direct shear tests were performed on the modified expansive soils with 4 concentrations of NaCl solution and KCl solution.The stressdeformation curve,shear strength line and shear strength index change curve were obtained.The test results showed that the shear strength of modified soil was generally lower than that of plain expansive soil.The proposed shear strength formula fitsted well with the test data,which also reflected the shear strength changes accurately.The influence of salt solution on the shear strength and cohesion of unsaturated expansive soil was achieved by changing the thickness of the electric double layer,the contact between soil particles and the structural characteristics.Finally,the micro mechanism of the shearing of expansive soils under condition of salt solution was further discussed.

Key words:unsaturated expansive soil;salt solution;direct shear test;shear strength

 盐溶液质量分数对非饱和膨胀土抗剪强度的影响_雷胜友.pdf