膨润土改性黄土衬里防渗性能室内测试与预测

试验测定了膨润土改性黄土试样的渗透系数，研究膨润土改性黄土用作废弃物填埋场衬里的可行性，为天然黏土匮乏地区防渗材料本土化提供依据。选取两种代表性黄土，即黏性较大的兰州黄土(LH)和砂性较大的榆林黄土(YH)，分别向其中添加不同比例的两种膨润土后击实成样，利用柔性壁渗透仪测定改性黄土的渗透系数，分析了改性黄土渗透系数随膨润土添加率增大的变化规律，确定了满足衬里防渗要求的膨润土添加率。利用扫描电镜照片统计了改性黄土的孔隙特征参数，发现添加膨润土后黄土中原有的大孔隙被充填或分隔成更多的中、小孔隙，有效阻滞了渗流液体通过，从微观结构的角度揭示了改性黄土渗透性降低的实质。依据实测数据建立了膨润土改性黄土的渗透回归模型，据此可以预测不同添加量的膨润土改性黄土的渗透系数。

Laboratory measurement and prediction to the permeability of bentonite-modified loess as a landfill liner

Mixing of bentonite to a native soil is a convenient and economic means to make an impermeable earthen liner for landfills in a region where natural clay is deficient.In this investigation,laboratory permeability tests were conducted on the compacted specimens of loess and bentonite mixtures to study the feasibility of bentonite-modified loess as a landfill liner material.Two kinds of loess soils with different grain size compositions,the Lanzhou loess soil(LH) and Yulin loess soil(YH),were mixed with vario...