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首要考慮對象。目前世界各國主要以單軸壓實法製作緩衝材料塊體，因壓實過程中材料與壓實模具間會產生壁面摩擦力，故無法有效獲得塊體實際壓實應力與密度之關係。故本研究依據瑞典單軸壓實法之概念，及直接量測法量測壁面摩擦力之方式設計壓實模具，進行不同膨潤土重量壓實試驗，並利用Gurnham提出之壓縮方程式，求取膨潤土無摩擦力影響之壓縮曲線。 同時針對可能影響壓實行為之因素進行分析探討。最後利用Tien等人(2004)所提出膨潤土-碎石混合物壓縮曲線之預測方法，預測純膨潤土添加不同體積比之花崗岩碎石及矽砂時的壓縮曲線。 Buffer materials are used to retard the migration of radionuclides emitted from high level wastes in a repository. Bentonite is the primary candidate for the buffer materials at the present day. The uniaxial compaction method is generally used to produce the bentonite block. The wall friction is produced between the materials and the compaction mold during the compaction process, so we can’t obtain the relationship between the actual compaction stress and the density of the bentonite block. The first target for this study is to search the literature of compaction techniques for buffer materials. Designing the compaction mold according to the concept of uniaxial compaction method. Adopting the direct method to measure the wall friction during bentonite block compaction and ejection. Using the compression equation developed by Gurnham to obtain the friction-free compressive curve of bentonite block. To analyze and discuss the effects that will influence the compaction behavior. To examine the effect of crushed rock content on the compaction characteristics, a series of uniaxial compaction tests for bentonite-crushed rock mixtures with different sand fractions (by weight) were performed. A prediction model based on micromechanics for predicting the compaction curves of bentonite-crushed rock mixtures was proposed by Tien et al. (2004).
