摘要
对NaCl、KCl、CaCl_(2)盐溶液饱和的钠质膨润土进行压缩固结试验,研究盐-荷载耦合作用对膨润土固结性能及饱和渗透性能的影响。结果表明:压实膨润土体积变形随固结应力的增大而下降,荷载等级跳跃对高浓度NaCl溶液浸泡下的膨润土体变性能的影响较为显著;NaCl、CaCl_(2)溶液作用下,随竖向固结应力的增大,压实膨润土试样由弹性状态转化为塑性状态,压缩系数先升高后降低,而KCl溶液作用下压缩系数一直降低;太沙基一维固结理论间接计算的膨润土饱和渗透系数为4.006×10^(-13) m/s~1.975×10^(-11) m/s,随溶液浓度增大,蒙脱石层间结合水含量降低,自由水流通路径拓宽,渗透系数相应增大;引入盐溶液下的修正有效应力,发现膨润土饱和渗透系数与有效应力之间可以用方程y=x^(-1)×(Alnx+B)统一表征,相关参数的确定有待进一步研究。
The consolidation tests of Na-bentonite saturated with NaCl,KCl and CaCl_(2) are conducted to study the influences of salt-load coupling effect on consolidation property and saturation permeability of bentonite.The results show that:The volume deformation of compacted bentonite decreases with the increase of consolidation stress,and the load grade jumps have a significant effect on the variable properties of bentonite soaked with high concentration NaCl solution.With the increase of vertical consolidation stress under the action of NaCl and CaCl_2,the compacted bentonite samples changed from elastic state to plastic state,and the compression coefficient first increased and then decreased,while the compression coefficient always decreased under the action of KCl solution.The saturation permeability coefficient of bentonite indirectly calculated by Terzaghi one-dimensional consolidation theory ranges from 4.006×10~(-13) m/s~1.975×10~(-11) m/s.With the increase of solution concentration,the content of interlayer bound water of montmorillonite decreases,the free water flow path widens,and the permeability coefficient increases correspondingly.By introducing the modified effective force in salt solution,it is found that the equation y=x~(-1)×(Alnx+B) can be used to describe the saturated permeability coefficient of bentonite and the effective stress.
作者
胡志杰
项国圣
付文青
王浩
李华健
Hu Zhijie;Xiang Guosheng;Fu Wenqing;Wang Hao;Li Huajian(Department of Civil Engineering,Anhui University of Technology,Maanshan,Anhui 243002,P.R.China;College of Civil Engineering,Tongji University,Shanghai 200092,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2023年第6期1851-1858,共8页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(41702311)
中国博士后基金面上项目(2019M660096)。
关键词
钠质膨润土
固结
体积变形率
饱和渗透系数
修正有效应力
Na-bentonite
consolidation
volume deformation rate
saturated hydraulic conductivity
modified effectivestress
