高放射性廢料於地下深層處置中常利用緩衝材料阻隔放射性核種外移，目前之候選緩衝材料以膨潤土為主要對象。目前世界各國以單軸壓實技術來壓製緩衝材料塊體，因壓實過程中受壁面摩擦力之影響，使得塊體內部密度不均勻，而影響了緩衝材料塊體之品質；同時皂土內含有大量之蒙脫石，故皂土為具有高塑性、膨脹性之黏土材料。為了瞭解含水量對皂土之影響，因此本研究以直接量測法來探討不同含水量皂土於單軸壓實過程中之壓實行為。 由郭明峰(2004)提出之「長徑比外插法」與吳柏林(2005)提出之「積分平均法」，去求得不同含水量皂土之無壁面摩擦力影響之壓縮曲線，以代表不同含水量皂土之真正壓實行為。 最後本研究利用Tien等人(2004)所提出一套皂土-碎石混合物之預測模式，來預測純皂土添加不同重量比之花崗岩碎石及矽砂時之壓縮曲線。 Buffer materials are used to separate the migration of radionuclides emitted from high level wastes in a repository. Bentonite is the primary candidate for the buffer materials at present. The uniaxial compaction method is generally used to produce the bentonite blocks over the world. Since a density within the block is not even by the influence of the wall friction forces during the compaction period and then influenced the quality of buffer blocks. At the same time, a large number of montmorliionites is included into bentonite so that the clay materials of bentonite become high plasticity and expansion. Therefore, the direct method is used to find out the compaction behavior of bentonite in cases of different water content during the compaction test in the study.Compression curves of bentonite in different water contents are unable to represent real behavior of bentonite affected by the wall friction force. In the study, “Aspect ratio method” by Guo (2004) and “Integral average method” by Wu (2005) are used to obtain friction-free compression curve of bentonite in different water contents to represent real behavior of bentonite. Finally, the model by Tien et al. (2004) is used to predict compression equations of bentonite-crushed rock mixtures in this study with different granite and slica sand fractions in different weight ratios.
