膨胀条件下混合型缓冲回填材料的渗透特性

 选取内蒙古高庙子膨润土(GMZ001膨润土)，分别向其中添加0%，10%，20%，30%，40%，50%的石英砂，采用电子压力试验机在20 MPa荷载下静力压实制样，利用柔性壁渗透仪实测300 kPa围压条件下膨润土–石英砂混合物的渗透系数和体积膨胀变化。研究表明，在0%～50%掺砂率范围内，GMZ001膨润土–石英砂混合物的渗透性随掺砂率增大没有明显的变化，能够满足高放废物处置缓冲回填材料低渗透性的要求。引入有效黏土密度的概念，分析掺砂率和干密度对渗透系数的共同影响可知，膨润土–石英砂混合物渗透系数的对数值与有效黏土密度存在良好的线性衰减关系。结合压实试验结果发现，GMZ001膨润土–石英砂混合物的渗透系数为掺砂率的单值函数，据此提出不同压实条件下GMZ001膨润土–石英砂混合物渗透系数的预测关系式，期望为混合型缓冲回填材料的配比优化提供理论依据。

PERMEABILITY OF BENTONITE-SAND MIXTURES AS BACKFILL/BUFFER MATERIAL IN HLW DISPOSAL UNDER SWELLING CONDITIONS

The Gaomiaozi bentonite(GMZ001 Bentonite) from Inner Mongolia was mixed with quartz sand at different sand mixing ratios of 0%,10%,20%,30%,40% and 50%.The soil specimens were prepared by compacting the mixtures under a pressure of 20 MPa using an electronic compression press.The permeability coefficient and the swelling volume of the mixtures under confining pressure of 300 kPa were determined using a flexible-wall permeameter.Test results show that there is no significant change in permeability coefficient...