微电场效应对土体渗透特性的影响

Micro-electric field effect on the soil permeability characteristics

利用蒸馏水和不同电解质离子浓度的孔隙液对饱和人工土进行渗透试验,研究不同矿物成分及离子浓度的极细颗粒土渗流的微电场效应。研究发现:相同固结压力时,孔隙液浓度n越大,固结排水速度越快,渗流的微电场效应越明显,且孔隙液浓度在中段时,土样渗透系数的增长速度较快。粘土矿物成分含量的变化也会导致颗粒表面微电场的改变:高岭土含量较高时,颗粒之间存在自由水而出现"渗孔",孔隙液浓度增大导致渗透性显著提高;反之,膨润土含量较高时,孔隙液浓度对渗透性的影响不明显。

Through the test on the permeability of the saturated artificial soil with distilled water and different electrolyte ion concentrations,the micro electric field effect of the very fine particles with different mineral compositions and ionic concentrations is studied. It＇s found that under the same consolidation pressure,the pore concentration n is larger and consolidated drain is faster,and the micro seepage field effect is more obvious. When the concentration of pore solution is in the middle,the permeability coefficient of the soil sample grows faster.Clay mineral composition changes lead to the electric field changes of the tiny particles on the surface. The high content of kaolin leads to the free water in the particles,and ‘seep holes＇ appear. The increasing of pore solution concentration improved permeability significantly. Conversely,when the bentonite content is higher,the pore solution concentration effect on the permeability is not obvious.