中文摘要：

为了研究高碱性孔隙水对膨润土缓冲性能的影响及微观机理,采用浓度为0.6mol/L的NaOH溶液模拟碱性孔隙水,对初始干密度分别为1.50和1.70g/cm3的高庙子（GMZ）膨润土试样开展渗透试验.利用AutoPoreIV 9510型全自动压汞仪对试样的微观孔隙结构进行水银孔隙率定试验（MIP）,借助X射线衍射试验（XRD）对试样的矿物成分变化进行分析.由试验结果可见,GMZ膨润土试样的孔隙量与平均孔径呈近似双峰变化关系;膨润土经水化作用后,试样内部的孔隙率和大孔隙量均明显减少,小孔隙量增加;在碱溶液入渗作用下,膨润土内部的孔隙率增大,膨润土的有效成分——蒙脱石质量分数减少.研究表明,碱性孔隙水的长期入渗会逐渐溶解膨润土中的蒙脱石,增大膨润土的孔隙率,提高膨润土的长期渗透性,可能会导致膨润土的封闭和缓冲性能降低.

英文摘要：

The influence of hyper-alkaline solution on the properties of bentonite was analyzed from microscopic view. The AutoPore IV 9510 automatic mercury porosimeter was used in mercury intrusion porosimetry （MIP） conducted on compacted Gaomiaozi （GMZ） bentonite with the initial dry densities of 1.50 and 1. 70 g/cm3, and NaOH solution with a concentration of 0. 6 mol/L was applied to simulate hyper-alkaline pore water. The X-ray diffraction （XRD） was employed to analyze the composition alteration of samples. Test results showed that a two-peak shape was observed from curves of relationship between pore volume and the mean pore diameter. Compared to the initially unhydrated samples, the porosity and quantity of macro-pores obviously decrease in hydrated samples, while those of micro-pores increase a little. Compared to de-ion water, the infiltration of hyper-alkaline solution increases the porosity and decreases the smectite content in bentonite with a possible explanation of the smectite dissolution. Therefore, the bentonite submitted to long-term infiltration of hyper-alkaline pore water may lead to the alteration of montmorillonite and porosity, amplifying the permeability, and resulting in a weak ability of sealing and buffering.