高应力区巷道围岩失稳致灾演化的应变场响应及前兆信息识别研究

Rock or coal dynamic disasters have become increasingly serious, which restricts the safety production in coal mine. In terms of hazard evolution and disaster monitoring and early-warning, strain field as an important indicator of coal or rock unstability and failure is under restrictions owing to the lack of intensive study on the theory, method and technology. Our project intends to use optical fiber sensing technology to test the spatial and temporal characteristics of internal strain for the bursting coal or rock samples under the different loading conditions. Based on the joint results of multipoint ultrasonic test and acoustic emission locating test, the coupling correlation and evolution characteristics of the internal strain field, damage field and fracture field will be obtained contrastively. Then the meso-mechanism of unstability and failure of coal or rock and strain response precursor information will be revealed. Internal strain field distribution and variation of the surrounding coal and rock in high-stress roadway will be field tested and the response characteristics of strain indexes at different stages of rockbursting will be analyzed in order to present the evolution process of rockburst disaster. Strain criterion proof of coal or rock unstability and failure will be proposed and the preliminary research on the quantitative identification of strain precursor and the early-warning of rockburst risk in mining field will be carried out. Our research results have important theoretical and practical significance for enriching the theory and prevention techniques of rockburst.

日趋严重的煤岩冲击动力灾害制约矿山安全。应变或变形是反映受载煤岩体失稳及破坏的主要参量，但在理论、方法和技术研究上的不足，使其在表征煤岩冲击致灾演化、灾害监测及预警等方面受到限制。本项目测试并分析冲击煤岩试样加载过程中内部应变的时空分布特征，结合超声波和声发射定位的同步测试结果，对比研究煤岩样受载破坏内部应变场特征与其损伤场、裂隙场演化规律的相关性，揭示冲击煤岩失稳破坏的细观机制及应变响应前兆；现场实测冲击地压矿井高应力区域巷道围岩内部应变场的分布及变化规律，分析冲击地压孕育不同阶段各应变指标的响应特征，刻画冲击地压演化过程；开展基于内部应变场的采掘现场冲击危险前兆信息定量识别研究，提出冲击地压失稳的应变判据。研究成果对于丰富冲击地压理论及预防技术具有重要的理论和实践意义。

原位煤岩体受巷道掘进等工程扰动时应力状态会重新分布，由于不均质性和各向异性煤岩体不同区域的受力变形程度不相同，应变是反映煤岩体失稳及破坏的主要参量，但在理论、方法和技术研究上的不足，使其在表征煤岩冲击致灾演化、灾害监测及预警等方面受到限制。本项目开展了在单向、双向、循环加卸载等不同加载方式下对相似材料、冲击倾向性煤岩试样（完整样、含孔洞样）、混凝土试样的冲击破坏实验，测试试样受载过程中的内部应变，同时采集了试样受载过程中的表面应变、声发射和超声波信号，研究了试样受载过程内部应变的时-空演化规律，并对煤岩试样冲击破坏的应变前兆特征进行了定量识别，获取其临界失稳关键前兆信息；分析了煤岩试样变形破裂过程中内部裂隙场和损伤场的时空演化规律，进行受载试样破坏应变场与裂隙场、损伤场演化过程的相关性研究，揭示冲击煤岩失稳破坏的细观机制；开展了高应力区域巷道围岩内部应变的现场分布式测量，分析了内部应变场的分布及变化特征，研究失稳破坏全过程围岩内部实时应变、累计应变、应变速率等应变指标的变化规律，获取孕灾空间围岩变形发展不同阶段各应变指标的响应特征以及其与孕灾演化过程的相关性，揭示冲击地压致灾机理。分析了在工作面不同距离的围岩内部应变的变化规律以及加载全过程试样内部应变和表面应变的变化规律，研究了冲击地压孕育和激发阶段围岩内部应变的时空临界条件，对冲击危险应变前兆信息进行了定量识别，提出了冲击地压危险应变判据。研究成果对于丰富冲击地压理论及预防技术具有重要的理论和实践意义。