低放射性廢棄物坑道式處置的多重障壁包括廢棄物固化體、廢棄物包件(overpack)、處置設施、回填材料及天然障壁(岩層)，其中處置坑室(近場)所在的廢棄物包件與封閉用回填材料，由於受到地下水入侵及應力共同作用，且設計年限達三百年以上，其近場環境演化情節遠較一般土木工程或大地工程複雜。國內目前正積極推動低放射性廢棄物最終處置工作，亟需及早獲取本土化的回填材料參數，做為最終處置場設計之參考。 本研究將以台東樟原村日興土與美國懷俄明州膨潤土，混合台東地區硬頁岩碎石級配料，調配成不同黏土-碎石含量之回填材料，而後進行基本性質、夯實、膨脹率、回脹壓力、水力傳導度等試驗，依據試驗結果歸納其功能特性，一方面尋求回填材料之最佳配方，另一方面掌握本土回填材料之工程性質，並與國際間使用之回填材料加以比較。Engineered barriers for the final disposal of low-level radio active wastes include the solidified wastes, waste overpack, disposal facilities, and backfill material. The backfill material is expected to be subjected to the loading stress and groundwater intrusion. Due to the extremely long design life, the scenarios in the near-field of the disposal site are very complicated, relative to typical engineering works. Currently, officials in Taiwan are working actively on the final disposal of low-level radwastes. It is necessary that parameters of the backfill material be developed using locally available materials. Zhishin clay (日興土) and black hill bentonite will be used as raw clay materials in this study. Various amounts of the clay will be mixed with the Argillite sampled from Taitung to prepare for backfill material specimens. These specimens are then tested for material characteristics, compaction properties, free swelling, swelling pressure, and hydraulic conductivity to obtain the engineering characteristics of backfill material. Based on the evaluations, formulation of the backfill material can be developed. Also, the properties of the backfill material will be compared with those used by other countries to assure suitability. 研究期間 : 9801 ~ 9812
