Abstract Heat–cool (H–C) cycle is a serious natural weathering mechanism for rock engineering in temperate desert climate; meanwhile, engineering rocks usually involve responses to impact loads arising from blasting operation, mechanized construction, and seismic oscillation. Considering the universality and destructiveness of rock failure caused by H–C cycle weathering coupled with dynamic loading, split Hopkinson pressure bar tests were conducted for sandstone with various H–C cycles. Additionally, hydrothermal coupled damage (D) was defined based on variation of total import strain energy. Energy evolution, damage, and microscopic characteristics of sandstone after diffierent H–C cycles were studied. Finally, the microcosmic structure changes of sandstone after various H–C cycles are compared by means of scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) technology. Results show that decreasing rate of total import strain energy in high temperature group is significantly larger compared with that in low temperature group and moderate temperature groups. Repeated H–C cycles produce the thermal stress at the mineral boundary constantly and fracture along the boundary of the mineral particle according to the SEM and EDS results.

中文翻译：

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热液耦合对砂岩能量演化、损伤及微观特征的影响

摘要 热-冷（H-C）循环是温带沙漠气候下岩石工程中一种严重的自然风化机制；同时，工程岩石通常涉及对爆破作业、机械化施工和地震振荡产生的冲击载荷的响应。考虑到 H-C 循环风化加上动载荷引起岩石破坏的普遍性和破坏性，对不同 H-C 循环的砂岩进行了劈裂霍普金森压杆试验。此外，水热耦合损伤 (D) 是根据总输入应变能的变化定义的。研究了不同 H-C 循环后砂岩的能量演化、损伤和微观特征。最后，通过扫描电子显微镜（SEM）和能谱仪（EDS）技术比较了不同H-C循环后砂岩的微观结构变化。结果表明，与低温组和中温组相比，高温组总输入应变能下降率显着较大。根据SEM和EDS结果，重复的H-C循环在矿物边界处不断产生热应力并沿矿物颗粒边界断裂。