接缝对高压实膨润土工程屏障自封闭性能的影响

 以高庙子膨润土为研究对象，采用自主研制的多功能膨胀–渗透仪，对不同初始干密度的试样进行不同接缝宽度条件下的膨胀力和渗透试验，并对水化后的膨润土进行水银孔隙率定试验，从微观结构层面分析接缝对膨润土渗透性的影响机制。结果表明：接缝的存在将导致膨润土的膨胀力减小、渗透性增大，从而降低膨润土在处置库中的自封闭性能；在水化过程中，接缝的存在会引起膨润土内部孔隙大小和数量的变化，宏观表现为膨润土渗透性增大。

INFLUENCE OF JOINT ON SELF-SEALING BEHAVIOUR OF HIGHLY COMPACTED BENTONITE IN ENGINEERING BARRIER

An experimental study was carried out on the compacted samples of Gaomiaozi(GMZ) bentonite.In order to do this,a self-made multifunctional swell and permeability apparatus was developed in the laboratory.The swelling tests and permeability tests were both performed with respect to different initial dry densities and different widths of joints.After hydration tests,the mercury intrusion porosimetry(MIP) test was carried out to study the influencing mechanism of joints on the permeability of bentonite.The results show that the existence of joints will lead to expansion force of bentonite decreases,the permeability increases and thus reduce the self-sealing performance of bentonite in the engineering barrier of repository.During the hydration processes,the existence of joints will change the size and quantity of pores in bentonite and cause its permeability increase macroscopically.