ISS加固红色黏土的孔隙分布试验研究

武汉市汉阳区存在着大量由冲洪积所形成的网纹状红色黏土，它遇水膨胀、软化，失水收缩、开裂。为了减小红色黏土不良性质对土路、公路路基和防渗工程造成的危害，采用离子土壤固化剂（ISS）对红色黏土进行处理。对经ISS处理前后的红色黏土，调成液限状态，进行液氮冷冻真空升华干燥，分析比表面及孔隙分布，观察微结构并统计裂隙。试验结果表明：经ISS处理后，红色黏土的结合水膜减薄，土粒之间的吸引力增强，从而使红色黏土的相对密度增大。减薄结合水膜的土颗粒在ISS连接力作用下，使红色黏土团聚结构和堆叠结构更加紧密，比表面积减小、累积孔隙体积和平均孔直径减小，从而提高了红色黏土的无侧限抗压强度和抗剪强度。

Pore diameter distribution test of red clay treated with ISS

There are a large number of red clays of quaternary from alluvial-diluvial in Hanyang of Wuhan City. When meeting water, it will swell and soften; when losing water, it will shrink and crack. In order to reduce the harm to dirt road, road bed and anti-seepage engineering, ionic soil stabilizer (ISS) is taken to reinforce the red clay. The red clay is dried in the state of nitrogen and vacuum before and after treatment with ISS. Its specific surface area and pore diameter distribution were analyzed; its microstructure and fracture were observed. The results show that after treated by ISS, the adsorbed water film thins and attraction of clay particles increases, which make the specific density increase. In the connectivity of ISS, the structures of aggregate and stacked of red clay become more closely; the specific surface area, cumulative pore volume and average pore diameter decrease; thereby the unconfined compressive strength and shear strength of red clay were enhanced.