γ辐照老化对高庙子天然钠基膨润土力学强度和变形特性影响研究

发布时间：2018-05-23 19:51

本文选题：辐照老化 + 钠基膨润土　；参考：《岩土力学》2017年10期

【摘要】：为探究高放核废物深地质处置缓冲材料的长期稳定性,以内蒙古高庙子(GMZ)天然钠基膨润土为研究对象,揭示了γ辐照老化作用对高压实天然钠基膨润土样品力学强度和变形特性的影响。采用钴源在室温下对该膨润土进行不同累积剂量的辐照作用,分析了辐照前、后膨润土的矿物成分变化,并开展了三轴剪切以及膨胀变形试验。结果表明:γ辐照老化作用引起膨润土部分矿物成分的变化,蒙脱石微观结构稳定性降低并转化为更稳定的硅酸盐和硅铝酸盐矿物;膨润土经过辐照作用后剪切强度有所增长且随辐照剂量增大,矿物成分发生了变化,同等围压下膨润土的剪切峰值强度逐渐提高;随着围压的增大,强度增长的幅度逐渐变缓,辐照剂量对强度的影响减弱,表明围压对膨润土强度的增长有一定的抑制作用;由于辐照后蒙脱石的含量减少,膨润土的膨胀变形性能相应减弱,即膨胀力、自由膨胀应变、有荷膨胀应变等指标降低。
[Abstract]:In order to explore the long-term stability of buffer material for deep geological disposal of high-level radioactive nuclear waste, the natural sodium bentonite of GMZ, Inner Mongolia, was taken as the research object. The effects of 纬 irradiation aging on the mechanical strength and deformation characteristics of natural sodium bentonite samples with high pressure were revealed. The mineral composition changes of the bentonite before and after irradiation were analyzed and triaxial shear and expansion deformation tests were carried out by using cobalt source at room temperature to irradiate the bentonite in different accumulative doses. The results show that the change of some mineral composition of bentonite caused by 纬 -irradiation aging results in the decrease of microstructure stability of montmorillonite and its transformation into more stable silicate and aluminate minerals. After irradiation, the shear strength of bentonite increases and the mineral composition changes with the increase of irradiation dose. The shear peak strength of bentonite increases gradually under the same confining pressure, and the amplitude of strength increases slowly with the increase of confining pressure. The effect of irradiation dose on the strength of bentonite is weakened, which indicates that confining pressure has a certain inhibitory effect on the growth of bentonite strength, and the swelling deformation property of bentonite decreases due to the decrease of montmorillonite content after irradiation, that is, expansion force and free expansion strain. The expansion strain and other indexes are reduced.
【作者单位】：西南科技大学土木工程与建筑学院;西南科技大学工程材料与结构冲击振动四川省重点实验室;中交隧道工程局有限公司华南分公司;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;中国辐射防护研究院中核高放废物地质处置评价技术重点实验室;重庆大学资源及环境科学学院;
【基金】：十三五国家重点研发计划(No.2017YFC0804600) 四川省科技支撑计划项目(No.2016GZ0157) 西南科技大学研究生创新基金资助(No.16ycx078)~~
【分类号】：TU443

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