摘要
为了研究盐渍土的孔隙特征,在乾安地区选择冻深范围内的代表性剖面,取样并进行盐渍土基础物理性质测试和压汞试验,得到地表以下冻深范围内不同深度处土体基本性质及孔隙分布特征。试验结果表明:盐渍土的原状剖面表观形态、粒度成分、土体孔隙分布特征均呈现一致的三层分带;天然状态下碳酸型盐渍土的孔径可分为微、小、中、大与超大孔隙5级,界限孔径依次为0.040、0.400、4.000、40.000μm;随着深度增大,3层土体的孔隙分布曲线峰值个数减少,各深度土体的孔隙以大孔隙为主,中孔隙次之,超大孔隙体积分数仅在表层较高但整体低于中孔隙,微、小孔隙体积分数较低且在小范围波动。分析认为自重应力对土体结构的压密作用、蒸发淋滤产生水分及细粒的迁移、气候变换导致的冻融循环作用是影响研究区孔隙分布特征的三大因素。
To study the pore characteristics of natural bicarbonate saline soil in Qian’an area,a representative soil profile within the frozen depth was selected and sampled.The particle composition and pore size distribution of undistributed soil at different depths were measured by laser diffraction particle size analyser and mercury intrusion porosimetry,respectively.The results show that a consistent three-layer stratification characteristics exists in the undisturbed profile morphology,grain size composition and soil pore distribution.The pore size of soil samples could be grouped into micro,small,medium,macro and super macro pores,with limit pore diameter of 0.040,0.400,4.000 and 40.000μm,respectively.With the increase of depth,the number of peak values of pore distribution curves decreases along the three layers of soil.The volume fraction of super macro pores is relatively higher only near the surface layer and lower than that of medium pores as a whole.The volume fraction of micro and small pores both decreased along the depth and fluctuated within a narrow range.It is concluded that the compaction effect of gravity stress on soil structure,the dry-wet cycles due to evaporation and leaching,and the freeze-thaw cycles caused by climate change are the three major factors affecting the pore distribution characteristics.
作者
陈剑平
李兴华
王清
韩岩
刘经
韩梦霞
Chen Jianping;Li Xinghua;Wang Qing;Han Yan;Liu Jing;Han Mengxia(College of Construction Engineering,Jilin University,Changchun 130026,China)
出处
《吉林大学学报（地球科学版）》
CAS
CSCD
北大核心
2023年第2期491-501,共11页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(41820104001,41627801)
吉林省水利厅资助项目(126002-2020-0001)。
关键词
乾安
碳酸型盐渍土
孔隙特征
孔隙分布形成机理
Qian’an area
bicarbonate saline soil
pore characteristics
formation mechanism of pore distribution
作者简介
陈剑平(1957-),男,教授,博士生导师,主要从事岩体工程地质方面的研究,E-mail:chenjp@jlu.edu.cn;通信作者:王清(1959-),女,教授,博士生导师,主要从事土体工程地质方面的研究,E-mail:wangqing@jlu.edu.cn。
