| 岩石加速破裂行为的物理自相似律 |
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| 引用本文： | 杨百存,秦四清,薛雷,陈竑然,吴晓娲,张珂.岩石加速破裂行为的物理自相似律[J].地球物理学报,2017,60(5):1746-1760. |
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| 作者姓名： | 杨百存 秦四清 薛雷 陈竑然 吴晓娲 张珂 |
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| 作者单位： | 1. 中国科学院地质与地球物理研究所 中国科学院页岩气与地质工程重点实验室, 北京 100029;2. 中国科学院大学, 北京 100049 |
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| 基金项目： | 国家自然科学基金项目（41572311，41302233）资助. |
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| 摘 要： | 掌握岩石变形破坏过程中体积膨胀点至峰值强度点之间加速破裂行为的演化规律,是实现地质灾害物理预测的关键.本文考虑裂纹张开和闭合两种情况,基于断裂力学建立了三轴应力作用下裂纹扩展临界尺度与等效应力的关系.对微元体破坏概率,分别采用以等效应力表达的Weibull分布函数和裂纹尺度分形函数,通过对比导出了形状参数m与裂纹分布分维D_f关系的表达式.一个有趣的发现是,岩石峰值强度点与体积膨胀点应变比仅与m或D_f有关.对岩石蠕变或准蠕变破坏,合理的m值范围为1.0,4.0],在此范围内应变比近似为常数1.48,该常数是描述不同尺度岩石加速破裂规律的物理自相似常数.实例分析表明,基于岩石加速破裂规律构建的多锁固段脆性破裂理论,其适用性广,尤其在崩滑和大地震预测领域,具有良好应用前景.此外,本文给出了b值与m值定量关系,以解释b值的物理意义,并探讨将其用于地震预测的可行性.
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| 关 键 词： | 等效应力 岩石加速破裂行为 物理自相似 常数1.48 多锁固段脆性破裂 |
| 收稿时间： | 2016-11-26 |
A physical self-similarity law describing the accelerated failure behavior of rocks |
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| YANG Bai-Cun,QIN Si-Qing,XUE Lei,CHEN Hong-Ran,WU Xiao-Wa,ZHANG Ke.A physical self-similarity law describing the accelerated failure behavior of rocks[J].Chinese Journal of Geophysics,2017,60(5):1746-1760. |
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| Authors: | YANG Bai-Cun QIN Si-Qing XUE Lei CHEN Hong-Ran WU Xiao-Wa ZHANG Ke |
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| Institution: | 1. Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;2. University of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | The key to predicting geological hazards is to master the evolution law of accelerated failure behavior between the volume expansion and peak strength points of rocks. Taking into account both cases of crack opening and closure, respectively, we propose a relationship between the critical scale of crack propagation and equivalent stress under the triaxial loading condition by means of fracture mechanics. When the microelement failure probability is described respectively by the Weibull's distribution function expressed by the equivalent stress and the fractal function of crack scale, a general expression between the Weibull's shape parameter m and the fractal dimension Df of crack distribution is derived by comparison. An interesting finding is that the strain ratio of the peak strength point to the volume expansion point is only related to m or Df. The reasonable range of m-values is 1.0, 4.0] for the creep or quasi-creep failure of rocks, where the strain ratio approximately equals to a constant, 1.48. It is emphasized here that the constant 1.48 is a physical self-similar one to describe the accelerated failure law of rocks with different scales. The case study demonstrates that the brittle failure theory of multiple locked patches developed on the basis of the accelerated failure law can be used to predict the occurrence of rockfalls, landslides and major earthquakes. In addition, a quantitative relationship between the b-value and m-value is put forward for explaining the physical implications of the b-value and discussing the feasibility of applying it to earthquake prediction. |
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| Keywords: | Equivalent stress Accelerated failure behavior of rock Physical self-similarity The constant 1 48 Brittle failure of multiple locked patches |
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