孔径分布对软黏土渗透特性的影响分析  

Analyses of the effect of pore-size distribution on permeability of soft clays

作　　者：金盼 陈波 胡云世 JIN Pan;CHEN Bo;HU Yunshi(College of Civil Engineering and Architecture,Quzhou University,Quzhou,Zhejiang 324000,China)

机构地区：[1]衢州学院建筑工程学院,浙江衢州324000

出　　处：《水文地质工程地质》2018年第4期86-93,共8页Hydrogeology & Engineering Geology

基　　金：浙江省基础公益研究计划项目资助(LGG18D020001);国家自然科学基金项目资助(41402271);衢州学院中青年学术骨干培养基金项目资助(XNZQN201514)

摘　　要：用单向固结仪对取自不同地区的三种软黏土原状样和重塑样分别开展了固结渗透试验,得到不同土样的固结曲线和压缩曲线,推算土样在不同固结压力下的渗透系数。试验结果表明:相同应力时,土体的结构性使原状样的渗透系数明显大于相应重塑样的渗透系数,且随着固结压力的增大,两者的差距逐渐减小;原状样和重塑样的渗透系数与孔隙比的变化模式基本一致,但同一孔隙比下原状样的渗透系数大于相应的重塑样的渗透系数,比较浦东软黏土原状样和重塑样在相近孔隙比下的孔径分布曲线后确认:这是由于它们的孔径大小及分布存在明显差异引起的,且通过比较相同孔隙比下原状样和重塑样的大孔隙体积含量可合理地解释上述试验结果。最后,用简单表述土体的孔径大小及分布(土体的组构)的参考孔隙比e*10对多种软黏土的渗透指数Ck进行整理后,发现多种软黏土的原状样和重塑样均为一条相关度极高的c_k-e*10直线,说明用参考孔隙比e*10可很好地反映土体的组构对软黏土渗透特性的影响。The oedometer tests on undisturbed and reconstituted samples of three soft clays obtained from different districts with different sampling methods were conducted,and the compression curves and the coefficients of permeability under different consolidation pressures were gained.The test results show that the coefficients of permeability of the undisturbed samples are much larger than those of the reconstituted samples for the soil structure at the same pressure and the gap of coefficients of permeability will be smaller with the increasing consolidation pressure.The coefficients of permeability of the undisturbed and reconstituted samples are different at the same void ratio although they have the similar rule between the coefficient of permeability and void ratio.It can reasonably be explained by the difference in large pore-size volume between the undisturbed and reconstituted samples,which can be calculated from the pore-size distribution curves obtained from the mercury intrusion porosimetry tests on the Shanghai soft clay.Finally,the reference void ratio e10^*,which is used to simply illustrate the soil fabric,is introduced to deal with the permeability change indices from different soft clays.The unique c k-e10^*curve with high relation,no matter undisturbed samples or reconstituted samples,shows that the reference void ratio e10^*is a reasonable parameter to illustrate the fabric effect on the permeability characteristic of soft clay.

关 键 词：原状样 重塑样 渗透系数 孔径分布 参考孔隙比 

分 类 号：TU411.4[建筑科学—岩土工程]