Granite is an ideal host rock for high-level radioactive waste (HLW) repositories. In the deep environment of HLW repositories, granite is subjected to variable temperature and hydraulic pressure. In order to investigate the influence of temperature and hydraulic pressure on the elastoplastic behavior of the Beishan granite, the present paper implemented a set of triaxial compression experiments at various temperatures and hydraulic pressures corresponding to the environment of HLW repositories. The deformation processes, damage evolution, elastic coefficients, and strength of the Beishan granite were analyzed, resulting in a limited change versus temperature and hydraulic pressure. The residual strengths of granite are similar, but a higher temperature surpasses about 70 °C degrades the friction strength of granite. Evidence from the acoustic emission (AE) hits shows the damage rate is accelerated by improved temperature and hydraulic pressure. According to the experiment-based mechanism, a modified elastoplastic model was proposed which considered thermal pressurization and changeable compressibility. The results of computation based on the proposed model match well the experiment data.

中文翻译：

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温度和水压影响下北山花岗岩弹塑性行为的洞察


花岗岩是高放废物（HLW）处置库的理想母岩。在高放废物处置库的深层环境中，花岗岩受到不同的温度和水压的影响。为了研究温度和水压对北山花岗岩弹塑性行为的影响，针对高放废物库环境，进行了一组不同温度和水压下的三轴压缩实验。对北山花岗岩的变形过程、损伤演化、弹性系数和强度进行了分析，结果表明其相对于温度和水压的变化有限。花岗岩的残余强度相似，但超过约 70 °C 的较高温度会降低花岗岩的摩擦强度。声发射（AE）击中的证据表明，温度和液压的提高会加速损坏率。根据基于实验的机理，提出了考虑热加压和可变压缩性的修正弹塑性模型。基于该模型的计算结果与实验数据吻合良好。