【摘要】 氡气是深部地下洞室建设过程中岩石破裂产生的污染性、放射性气体，深部岩体在高应力下普遍发生剪切破裂，然而，氡气释放量与岩石剪切破裂演化的相关性尚不清晰。针对这一问题，分析了完整锦屏大理岩和白鹤滩玄武岩两类岩石的放射性核素活度。自主设计了完整岩石直接剪切试验系统，并同步测量岩石破裂过程中的氡释放量。讨论了岩石剪切破裂面表面积与累积氡浓度的相关性。试验结果表明，在法向荷载相同的条件下，岩石中氡释放量随剪切位移的增大而变化，总体呈现在加载初期略有增加后小幅回落，再大幅增加至峰值释放水平，试样破坏后随着剪切位移的发展下降至稳定水平的规律。随着法向荷载的升高，初始氡浓度和峰值氡浓度均呈线性增长的趋势。通过对声发射特征参数RA-AF分布的研究，发现岩石剪切破裂面表面积与累积氡浓度具有相似的发展变化趋势。岩石剪切破裂过程中氡释放规律的揭示对深部工程排氡/隔氡设计具有重要指导意义。更多还原

【Abstract】 Radon is a polluting and radioactive gas released by rock fracture. Shear fracture is widely developed in surrounding rock mass of deep engineering. Nevertheless, the correlation between radon release and the shear fracture is undefined. In this study, the intact Jinping marble and Baihetan basalt were adopted as samples. Based on radionuclide content analysis, the intrinsic characteristics of radon emission were analyzed. Then a direct shear testing system was designed to synchronously measure radon release during rock fracture. The direct shear tests were carried out under different normal stresses. The relationship between shear fracture process and cumulative radon concentration was explored. The results indicated that radon release varied with the increase of shear displacement under the same normal stress. The general pattern showed a slight increase and fell in the initial loading phase, then increased rapidly to the peak release approximately corresponding to the peak of shear stress, and finally decreased to a stable level with the development of shear displacement after sample failure. The initial and peak radon concentrations increased linearly with the increase of normal stress. The same trend was found in shear failure surface area and cumulative radon concentration according to the rise angle(RA) value-average frequency(AF) distribution.更多还原