| 考虑应力变化速率的岩石脆性评价指标 |
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| 引用本文： | 匡智浩,李邵军,杜灿勋,邱士利,吝曼卿,杜三林.考虑应力变化速率的岩石脆性评价指标[J].岩土力学,2022,43(Z1):293-300. |
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| 作者姓名： | 匡智浩 李邵军 杜灿勋 邱士利 吝曼卿 杜三林 |
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| 作者单位： | 1. 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，湖北 武汉 430071；2. 中国科学院大学，北京 100049；
3. 华能西藏水电安全工程技术研究中心，西藏 林芝 860061；4. 武汉工程大学 资源与安全工程学院，湖北 武汉 430073 |
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| 基金项目： | 国家自然科学基金资助项目（No.U1765206，No.41877256）；湖北省重点研发计划项目（No.2020BCB078）；中国科学院重点部署项目（No.KFZD-SW-423）。 |
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| 摘 要： | 脆性作为岩石的重要的力学指标，对深部岩体性态评价以及灾害预防具有重要意义。岩石应力?应变曲线能够很好地表征岩石的脆性。考虑到现有基于应力?应变曲线的脆性指标大多都只对曲线的一部分进行分析，且少有指标能够准确地应用于岩石II类曲线中，对整体判断的缺乏可能会导致工程应用上适应性及可靠性不足的情况。针对现有脆性指标普遍存在的物理意义模糊、评估结果与岩石脆性的关系非连续等问题，综合考量岩石应力?应变曲线中峰前应力上升速率、峰后应力跌落速率以及峰值点应变值对岩石脆性的影响，提出了一种物理意义明确、计算结果与岩石脆性之间的关系是单调且连续的岩石脆性指数计算方法。选取国内外常用脆性指标对锦屏II级水电站大理岩和某铁路隧道花岗岩、变质砂岩以及片麻岩的单轴压缩试验数据进行脆性评价后进行比较，验证了指标的适用性。进一步将提出的指标应用于常规三轴试验条件下大理岩脆性分析，结果表明，该指标不仅能够量化和分类不同岩石的脆性特征，还能表征围压对岩石脆性的抑制作用。
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| 关 键 词： | 岩石脆性指标 锦屏II级水电站 铁路隧道 全应力?应变曲线 应力变化速率 |
| 收稿时间： | 2021-07-04 |
| 修稿时间： | 2021-08-21 |
Evaluation index of rock brittleness considering stress change rate |
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| KUANG Zhi-hao,LI Shao-jun,DU Can-xun,QIU Shi-li,LIN Man-qing,DU San-lin.Evaluation index of rock brittleness considering stress change rate[J].Rock and Soil Mechanics,2022,43(Z1):293-300. |
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| Authors: | KUANG Zhi-hao LI Shao-jun DU Can-xun QIU Shi-li LIN Man-qing DU San-lin |
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| Institution: | 1. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. Huaneng Tibet Hydropower Safety Engineering Technology Research Center, Nyingchi, Tibet 860061, China; 4. School of Resources and Safety Engineering, Wuhan Institute of Technology, Wuhan, Hubei 430073, China |
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| Abstract: | As an important mechanical index of rocks, brittleness is of great significance for deep rock mass behavior assessment and disaster prevention. The stress-strain curve of rock can well represent rock brittleness. Considering that most of the existing brittleness indicators based on stress-strain curves only analyze a part of the curve, and few indices can be accurately applied to the rock II type curve, lack of overall consideration may lead to the inadequate adaptability and reliability in engineering application. In order to solve those problems, such as the unclear physical meaning and the discontinuous relationship between the evaluation results and rock brittleness of the existing brittleness indices based on the complete stress-strain curve of rock, the influences of pre-peak stress rising rate, post-peak stress falling rate and peak strain on rock brittleness were analyzed, and a method of rock brittleness index with clear physical meaning, monotonous and continuous relationship between calculation results and rock brittleness was proposed. The commonly used brittleness indices were selected to compare the brittleness evaluation of the marble of Jinping II hydropower station and the granite, metamorphic sandstone and gneiss of a railway under uniaxial compression conditions, which verified the applicability of the index proposed. This novel brittleness index was further applied to the brittleness evaluation of marble under conventional triaxial test conditions. The results showed that this index could not only quantify and classify the brittleness characteristics of different rock types, but also characterize the confining pressure inhibition behaviors of rock brittleness. |
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| Keywords: | rock brittleness index Jinping II hydropower station railway tunnel complete stress-strain curve stress change rate |
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