摘要 温度对岩石强度有重要影响。实验室研究几乎普遍承认，由于各种“热损伤”机制，岩石在升高的温度下会变弱。大多数地下工程，如地热能开采、核废料处置库和深部采矿和洞穴的地下开挖，都在数百至数千米的深度实施，温度远未达到单独运行的高水平。热弱化因素。相反，一些实验研究报告称，在室温至 200 °C 的温和温度范围内，岩石可以通过加热得到强化，而不是减弱。尽管在地球物理和地质领域具有深远的科学和现实意义，岩石是否会因温度升高而被加强或削弱是难以捉摸的。强化效应背后的机制也知之甚少。我们对温度对岩石强度影响的实验室实验结果进行了全面的文献综述，重点是温和的温度状态。我们发现三种主要机制的双重影响及其相互作用可能会增加或降低岩石强度。然而，岩石强化或多或少是一种内在属性，取决于各种因素。我们还发现在升高的温度下存在从岩石强化到弱化的“过渡期”。这一发现对于地下工程项目很重要，因为许多设计参数的确定依赖于实验室测量的岩石强度。在工程项目中，温度对岩石强度的误解可能会导致结构和/或经济故障。为了准确评估岩石强度，未来的实验室研究应该集中在与原位地面条件相关的温和加热的岩石上。
Abstract Temperature has critical influences on rock strength. It is almost universally acknowledged from laboratory studies that rocks are weakened at elevated temperatures, as a result of the various “thermal damage” mechanisms. Most underground projects, such as geothermal energy extraction, nuclear waste repository and underground excavation for deep mining and caverns, are implemented at the depths ranging only from hundreds to thousands of meters where the temperature is far from reaching the high level for the sole operation of the thermal weakening factors. On the contrary, some experimental studies have reported that rock can be strengthened upon heating, rather than weakened in the mild temperature range from room temperature to 200 °C. Despite the profound scientific and practical significance in the geophysical and geological fields, whether rock will be strengthened or weakened in response to elevated temperature is elusive. The mechanisms behind the strengthening effect are also poorly understood. We carry out a comprehensive literature review on laboratory experimental results of the temperature effect on rock strength, with a focus on the mild temperature regime. We find that the dual effects of three major mechanisms and their interplay may either increase or decrease rock strength. Nevertheless, rock strengthening is more or less an intrinsic property depending on various factors. We also find that there exists a “transition period” at elevated temperatures from rock strengthening to weakening. This discovery is important for underground engineering projects, since the determination of a number of design parameters relies on the laboratory-measured rock strength. Misinterpreted temperature impact on rock strength in an engineering project potentially leads to structural and/or economical failure. For accurate evaluation of rock strength, future laboratory studies should concentrate on the mildly heated rock relevant to the in situ ground conditions.
