滨海相盐渍土强度机理分析

发布时间：2018-01-28 22:14

本文关键词： 道路工程盐渍土等效吸力剪切强度粉土黏土盐离子浓度　出处：《公路交通科技》2015年08期 　论文类型：期刊论文

【摘要】：针对不同含盐量和含水量的粉土和黏土进行直剪试验,分析盐渍土的黏聚力和内摩擦角与盐离子浓度、溶质吸力和基质吸力的关系,用非饱和土剪切强度理论和双电层理论解释剪切强度增加机理,提出盐溶液的有效应力概念和计算表达,建立有效应力与黏聚力的关系。粉土盐渍土和黏土盐渍土的直剪试验结果表明:粉土盐渍土的剪切强度参数与含盐浓度的关系是,当含盐浓度小于饱和浓度,剪切强度参数随含盐浓度增加基本不变;当含盐浓度大于饱和浓度,剪切强度参数随含盐浓度增加而增加。黏土盐渍土的剪切强度参数与含盐浓度的关系是,剪切强度参数随含盐浓度增加而增加,当含盐浓度大于饱和浓度,剪切强度参数随含盐浓度增加而增加得幅度大。粉土盐渍土和黏土盐渍土的剪切强度机理不同,粉土盐渍土的剪切强度增加是由盐结晶胶结和充填引起的,黏土盐渍土的剪切强度增加是由双电层作用和盐结晶胶结共同引起的。
[Abstract]:Direct shear tests were carried out on silt and clay with different salt content and water content, and the relationship between cohesion and internal friction angle of saline soil and salt ion concentration, solute suction and matrix suction was analyzed. The theory of shear strength of unsaturated soil and the theory of double electric layer are used to explain the increasing mechanism of shear strength, and the concept and expression of effective stress of salt solution are put forward. The direct shear test results of silt saline soil and clay saline soil show that the relationship between shear strength parameter and salt concentration of silt salt soil is that the salt concentration is less than saturation concentration. The shear strength parameters are almost unchanged with the increase of salt concentration. When the salt concentration is greater than the saturated concentration, the shear strength parameter increases with the increase of the salt concentration. The relationship between the shear strength parameter and the salt concentration is that the shear strength parameter increases with the increase of the salt concentration. When the salt concentration is higher than the saturated concentration, the shear strength parameter increases greatly with the increase of the salt concentration. The shear strength mechanism of the silt saline soil and the clay saline soil is different. The increase of shear strength of saline soil is caused by salt crystal cementation and filling, and the increase of shear strength of clay salt soil is caused by the action of double electric layer and salt crystal cementation.
【作者单位】：扬州工业职业技术学院;上海交通大学船舶海洋与建筑工程学院;河海大学闻天学院;南通市公路管理处;
【基金】：江苏省交通运输厅科研课题项目(2012Y01-1,2014Y04) 国家自然科学基金项目(41272318,41472251) 扬州市自然科学基金项目(YZ2014057)
【分类号】：U416.1;U412.221
【正文快照】： 0引言滨海相盐渍土是经过海水长期浸湿、淋滤形成的,含盐成分与海水一致,以Na Cl为主,通常含有较多的粉粒与黏粒[1]。滨海相盐渍土的孔隙水中含有大量的Na+,K+,Ca2+,Mg2+等可溶盐离子,造成盐渍土的特殊工程性质,主要有盐渍土地基溶陷和盐胀性[2-3]、盐渍土的腐蚀性[4-6]等,对

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