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| 采空区覆岩采动裂隙演化过程及其分形特征研究 |
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刘超1,2,李树刚1,2,许满贵1,2,张天军31,2,3
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1. 西部矿井开采及灾害防治教育部重点实验室,陕西 西安 710054;2. 西安科技大学 能源学院,陕西 西安 710054;3. 西安科技大学 理学院,陕西 西安 710054
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| 摘要: |
| 为了研究采空区覆岩采动裂隙形成过程中的演化规律,基于煤岩细观破裂力学特性的数值模拟方法,结合非线性的分形几何理论,研究了覆岩采动裂隙演化过程并定量地描述了其时空分布特征,结果表明：采动下覆岩不断劣化,其内部细观损伤积累最终引起覆岩破坏.采动裂隙演化过程中的声发射具有自相似性的分形特征,加载后其分维值首先小幅度的升高,随后急剧下降,尤其是在破坏前降到最低,该特性可作为评价覆岩破坏的有效指标.上述结果能很好地解释覆岩采动裂隙的演化机制,并指导灾害发生前覆岩稳定性发展趋势的预测预报等防治实践. |
| 关键词: 覆岩 采动裂隙 数值模拟 分形理论 演化规律 |
| DOI： |
| 分类号:TD32 |
| 基金项目:国家自然科学基金资助项目(51174157,51174158,51104118);中国博士后科学基金面上资助项目(2012M512017);陕西省教育厅自然科学研究项目(12JK0801);西安科技大学博士启动金项目(2012QDJ010);西安科技大学科研培育基金(201141) |
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| Research on mining crack evolution process and its fractal characterization of overlying strata in goaf |
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LIU Chao1,2,LI Shu-gang1,2,XU Man-gui1,2,ZHANG Tian-jun31,2,3
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1. Key Laboratory of Western Mine Exploitation and Hazard Prevention Ministry of Education,Xi′an 710054,China;2. School of Mining Engineering,Xi′an University of Science and Technology,Xi′an 710054,China;3. College of Science,Xi′an University of Science and Technology,Xi′an 710054,China)
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| Abstract: |
| In order to study the mining crack evolution process of the overlying strata in goaf, based on the numerical method for meso rupture mechanics characteristics of coal rock, combined with nonlinear fractal geometry theory, the evolution process of mining crack and quantitative description of the spatial and temporal characteristics were researched. The results show that the overlying strata deteriorated continuously under mining, simultaneously, the internal meso damage accumulation of rock eventually cause the overlying strata failure. The acoustic emission in the cracks evolution process is with self-similarity. The fractal dimension increases firstly with a small amplitude after loading, and then sharp declines, especially decreases to a minimum value before damage. It is considered to be a effective indicator in evaluation of overburden damage. By means of the overlying results, the overburden fractured evolutionary mechanisms are explained perfectly, and it is able to guide forecasting and control practice of rock stability before disasters. |
| Key words: overlying strata mining crack numerical simulation fractal theory evolution rule |
