摘要
为了探究不同地区盐渍土-混凝土界面的强度及变形差异,自制硫酸钠盐渍土与混凝土试样,将盐渍土在不同含盐量、初始干密度及法向应力条件下与混凝土进行一系列单调直剪试验。通过试验研究不同因素对界面抗剪强度的影响,并分析在不同含盐量下界面抗剪强度参数及剪胀性的变化规律。研究结果表明:含盐量对界面抗剪强度起到劣化作用,其劣化程度在土体孔隙溶液处于非饱和状态时随含盐量增大而减弱,而孔隙溶液饱和结晶时,劣化作用增强;盐渍土抑制了初始干密度对界面抗剪强度的增强作用;不同竖向应力下,含盐量为1%~4%的盐渍土对应界面的平均破坏剪应力是素土的0.71,0.75,0.86和0.77倍,界面盐蚀折减系数在0.68~0.88范围内变化;界面黏聚力随着含盐量的增加而增大,内摩擦角表现出与抗剪强度相同的变化趋势,并且界面黏聚力受含盐量影响效果更显著;在较低法向应力和较高含盐量下,界面出现剪胀现象,其余情况均表现为剪缩,剪缩量随法向应力递增,在含盐量为3%时取得最小值。界面剪胀角在含盐量0%~3%范围内随含盐量增加显著提升。此外较高法向应力对界面剪胀角存在抑制作用,并弱化含盐量对剪胀角的影响。
In order to explore the strength and deformation differences of the interface between saline soil and concrete in different areas,using self-made sodium sulphate saline soil and concrete samples,a series of monotonic direct shear tests were carried out under different salt contents,initial dry densities and normal stresses.The effects of different factors on the interfacial shear strength were studied,and the variation laws of the interfacial shear strength parameters and dilatancy under different salt contents were analyzed.The results show that the deterioration of the interfacial shear strength is caused by the salt content.If the pore solution of saline soil is in unsaturated state,the deterioration is weakened with the increase of the salt content.Otherwise,the degradation effect is increased.The enhancement effect of the initial dry density on the interfacial shear strength is inhibited by saline soil.The average failure shear stresses of the interface with salt contents of 1%to 4%under different vertical stresses are respectively 0.71,0.75,0.86 and 0.77 times that of plain soil,and the salt erosion reduction coefficient of the interface varies in the range of 0.68-0.88.As the salt content increases,the interfacial cohesion is enhanced,and the same trend as the shear strength is shown in the internal friction angle.In addition,the interface cohesion is more significantly affected by the salt content.Under the condition of a lower normal stress and a higher salt content,dilatancy is appeared in the interface,and shear shrinkage is shown in other cases.The shear shrinkage increases with the normal stress,and the minimum value is obtained when the salt content is 3%.The interfacial dilatancy angle increases significantly with the increase of the salt content in the range of 0%to 3%of the salt content.Besides,the increase of the interfacial dilatancy angle is restrained by a higher normal stress and the effect of the salt content on the dilatancy angle is weakened under the same condition.
作者
刘飞禹
赵川
孙宏磊
张诗珣
LIU Feiyu;ZHAO Chuan;SUN Honglei;ZHANG Shixun(College of Mechanics and Engineering Science,Shanghai University,Shanghai,200444,China;College of Civil Engineering,Zhejiang University of Technology,Hangzhou,Zhejiang 310023,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2022年第8期1680-1688,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52078285,51878402)。
关键词
土力学
盐渍土
含盐量
土-混凝土界面
剪切特性
盐蚀折减系数
soil mechanics
saline soil
salt content
interface between soil and concrete
shear characteristic
salt erosion reduction coefficient
