在恒容和自由膨胀条件下确定压实砂-膨润土混合物的非饱和导水率
Determining the unsaturated hydraulic conductivity of a compacted sand-bentonite mixture under constant volume and free-swell conditions
摘要：
在高放放射性废物深埋处置中，高度压实的砂-膨润土混合物通常被认为是可能的工程屏障。在原位，这些障碍物的饱和从他们最初的不饱和状态是一个复杂的流体力学耦合过程中，温度效应也发挥了作用。该过程的关键参数是屏障的非饱和导水率。本文采用等温入渗试验，根据瞬时剖面法确定了非饱和导水率。为了做到这一点，总吸力的变化进行了监测，在不同的位置沿土样通过使用电阻率相对湿度探头。进行了三个恒定体积的渗透试验，出乎意料的是，渗透过程中的导水率下降。在自由膨胀条件下进行的一项试验显示了相反的标准趋势。这些观察结果进行了解释润湿过程中的微观结构变化，无论是在恒定体积和自由溶胀条件下。
英文摘要：
Highly compacted sand-bentonite mixtures are often considered as possible engineered barriers in deep high-level radioactive waste disposals. In-situ, the saturation of these barriers from their initially unsaturated state is a complex hydro-mechanical coupled process in which temperature effects also play a role. The key parameter of this process is the unsaturated hydraulic conductivity of the barrier. In this paper, isothermal infiltration experiments were conducted to determine the unsaturated hydraulic conductivity according to the instantaneous profile method. To do so, total suction changes were monitored at different locations along the soil specimen by using resistivity relative humidity probes. Three constant volume infiltration tests were conducted showing, unexpectedly, a decrease of the hydraulic conductivity during infiltration. One test performed under free-swell conditions showed the opposite and standard trend. These observations were interpreted in terms of microstructure changes during wetting, both under constant volume and free swell conditions.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
