膨润土颗粒充填施工接缝的缓冲层膨胀力研究  

Study on the Swelling Pressure of the Buffer Layer with Technological Voids Filling with Bentonite Pellets in High-Level Radioactive Waste Barrier

作　　者：胡世祥 谈云志[1,2] 明华军[1,2] 吴军[1,2] 李辉[1,2] HU Shixiang;TAN Yunzhi;MING Huajun;WU Jun;LI Hui(Institute of Problematic Soils,China Three Gorges University,Yichang 443002,China;Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学特殊土土力学研究所,湖北宜昌443002 [2]防灾减灾湖北省重点实验室(三峡大学),湖北宜昌443002

出　　处：《三峡大学学报（自然科学版）》2024年第4期73-78,共6页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金项目(51979150,52279102);湖北省自然科学基金项目(2023AFD198,2024AFA004)。

摘　　要：在高放废物处置库中,缓冲层通常以高压实膨润土砌块拼接回填形成,这势必在金属罐、砌块、围岩之间留下不可忽略的施工接缝.通过在位于试验舱底的压实膨润土上部预留接缝,开展接缝充填膨润土颗粒工况下的试样膨胀力测试,以掌握膨润土颗粒充填施工接缝对缓冲层膨胀力特性的影响.研究结果表明:试样水化方向不同,膨胀力发展过程存在较大差异,但膨胀稳定时间差别不大;从接缝端入渗时,试样均表现出随注水时间增长,膨胀力逐步提升,直至稳定在最高膨胀力;随着接缝宽度增大,最终膨胀力出现显著降低,且膨胀稳定时间显著增加;在施工接缝中充填膨润土颗粒可显著提升缓冲层最终膨胀力,保证其“自密封”要求.The voids that inevitably occur during the construction of deep geological repositories for high-level radioactive nuclear waste have an impact on the swelling performance of the buffer layer.In this study,swelling pressure tests were carried out on compacted bentonite samples with technological voids on top.The voids were set to different thicknesses with or without bentonite pellets.The influence of hydrating through the void or through the part of the compacted bentonite opposite to the void were analyzed.Results shows that the way of hydration greatly affects the swelling behavior of bentonite,but there is no significant difference in the time for swelling stabilization.When water is sucked into the void of the sample,the swelling pressure increases gradually with increasing water injection time until it stabilizes at its maximum value.With increasing of the void thickness,the final swelling pressure notably decreases,and the swelling stabilization time significantly extends.Filling the technological voids with bentonite pellets during construction significantly enhances the final swelling pressure of the buffer layer,ensuring its“self-sealing”requirement.

关 键 词：高放处置库 施工接缝 膨润土颗粒 膨胀力 

分 类 号：TU43[建筑科学—岩土工程]