极细颗粒黏土渗流离子效应的试验研究

采用常规固结仪对孔隙液离子浓度对极细颗粒黏土渗流固结特性的影响进行试验研究，在相同试验条件下进行了4组孔隙液含NaCl浓度不同的膨润土试样固结性质的测试，得到了各试样的固结曲线，求得相应的固结系数，再由固结系数求得相应的渗透系数。通过对各组试样的渗透系数对比分析，结果表明，孔隙液离子浓度对土体的渗流性质有重要影响，土体的渗透系数随孔隙液离子浓度的增加而增大，存在明显的离子效应。试验结果分析认为，黏土颗粒表面的扩散双电层厚度随离子浓度变化而变化，可能是产生离子效应的主要原因。试验结果有助于分析土体渗流离子效应的起因，对改进和完善现有渗流固结计算理论有一定指导意义。

Experimental research on ion effects of ultrafine granular clay seepage

By using a conventional consolidation apparatus, seepage characteristics of ultrafine granular soil affected by ion concentration of pore solution are performed, and consolidation characteristics of four sets of bentonite samples of pore solutions with different contents of NaCl are tested under the same test condition. Consolidation curves and relevant consolidation coefficients are obtained; and seepage coefficients are obtained based on consolidation coefficients. The comparative analyses of hydraulic conductivity of samples of each group show that ion concentration is an important factor that influences on seepage. The hydraulic conductivity of soil increases as ion concentration increases. It is concluded that the change of the thickness of diffuse double layer on granular clay surface with ion concentration may be a key factor influencing on ion effects of granular soil seepage. The test results have contribution to understanding the origins of the ion effects on soil seepage, and are of guiding significance for improvement and perfection on existing seepage and consolidation theories of soil.