• 论文
主办单位:煤炭科学研究总院有限公司、中国煤炭学会学术期刊工作委员会
采掘工作面孕突过程地应力诱使煤体初始破坏动态响应机制
  • Title

    Dynamic response mechanism of initial failure of coal mass induced by in-situ stress in an outburst inoculation process of the working face for coal mining

  • 作者

    王超杰唐泽湘徐长航杨洪伟刘鲁坦

  • Author

    WANG Chaojie;TANG Zexiang;XU Changhang;YANG Hongwei;LIU Lutan

  • 单位

    中国石油大学(华东)机电工程学院河南神火煤电股份有限公司

  • Organization
    College of Mechanical and Electrical Engineering, China University of Petroleum (East China)
    Henan Shenhuo Group Co., Ltd.
  • 摘要

    工作面采动应力场诱发煤体初始破坏,作为突出发生的必要条件,揭示其细宏观动态力学过程依然存在巨大挑战。基于采掘工作面典型突出事故,构建了采动煤体损伤失稳过程多变应力载荷路径。采用PFC3D离散元软件开展了多工况多尺度下煤体损伤失稳可视化模拟,揭示了采动煤体损伤失稳动态响应规律,阐明了采动煤体裂纹动态演变行为,并基于采动下地应力诱使煤体初始破坏规律提出了突出防治技术展望。结果表明:采动煤体随主应力加卸载速率的变化,其破坏类型和破坏强度差异明显。应力渐进卸载过程,煤体宏观破断面呈现单斜面或共轭剪切面形式,且随卸载速率增加,煤体破坏强度降低。随应力双向同等速率渐进加载,单向突然卸载或保持一定残余应力状态下呈现宏观破断面与中间主应力方向平行,且卸载程度增加或残余应力降低引发煤体破坏强度降低。不同应力载荷下,煤体破坏过程随剪切和张拉裂纹先后出现,呈现张剪破坏。在采动煤体损伤引发失稳过程中裂纹动态演变过程呈现间歇性、渐进性和阵发性复合特征。裂纹整体发育过程可表征为初期新裂纹出现(间歇性−突增阶段)、裂纹扩展(渐进性−慢增阶段)以及贯通并扩展(阵发性−慢增阶段)、整体撕裂煤体过程(骤增阶段)。煤体力学强度被视为影响突出发生的一主控因素,地应力诱发采动煤体初始破坏的难易程度关键在于应力加卸载路径。单向主应力突然卸载或双向主应力渐进卸载,煤体最易发生初始破坏。基于此力学规律,提出可表征工作面突出煤体最危险状态的“采掘工作面突出预测理想采动模式”。

  • Abstract

    There is still a great challenge to reveal the micro-macro dynamic mechanical behavior of initial coal failure induced by mining stress field in working face as a necessary condition for the outburst occurrence. The multivariate stress loading paths for the damage and instability of mining coal were constructed based on the typical coal and gas outburst accident of mining face. PFC3D discrete software was used to carry out the visual simulation of damage and instability of coal under multiple working conditions and scales. The dynamic response law of damage and instability of mining coal was revealed, the dynamic evolution behavior of cracks in mining coal was clarified, and the prospect of outburst prevention technologies was put forward based on the initial failure process of coal induced by in-situ stress under mining. The results shown that the failure type and strength of the mined coal varied significantly with the loading and unloading rate of the principal stress. In the process of gradual unloading of stress, the macroscopic fracture surface of coal presented the form of single inclined plane or conjugate shear plane, and the failure strength of coal decreased with the increase of unloading rate. With the gradual loading in both directions of stress at the same rate, unidirectional sudden unloading or a certain residual stress maintaining state presented a macro fracture surface parallel to the direction of the intermediate principal stress. And the failure strength of coal decreased with the increase of the unloading degree or the decrease of the residual stress. Under different stress loaded, the tension-shear failure process of coal appeared successively with shear and tension cracks. In the process of instability caused by mining coal damage, the dynamic evolution of cracks presented intermittent, progressive and paroxysmal composite characteristics. The overall development process of cracks can be characterized as the initial appearance of new cracks (intermittent-sudden increase stage), crack expansion (gradual-slow increase stage), penetration and expansion (paroxysmal-slow increase stage), and the overall tearing process of coal (sudden increase stage). The mechanical strength of coal was regarded as one of the main controlling factors affecting the occurrence of outbursts. The difficulty of initial failure of coal induced by in-situ stress depended critically on the stress loading and unloading path. The coal was most prone to initial failure when the unidirectional principal stress was suddenly unloaded or the bidirectional principal stress was gradually unloaded. Based on this mechanical law, the “ideal mining mode of outburst prediction in mining working face” was proposed to represent the most dangerous state of coal in the working face.

  • 关键词

    煤与瓦斯突出煤岩瓦斯动力灾害突出防治动态损伤裂纹扩展

  • KeyWords

    coal and gas outburst;coal/rock-gas dynamic disaster;outburst prevention;dynamic damage;crack propagation

  • 基金项目(Foundation)
    国家自然科学基金资助项目(52104236);中国博士后科学基金资助项目(2020M672177);中央高校基本科研业务费专项资金资助项目(22CX06018A)
  • DOI
  • 引用格式
    王超杰,唐泽湘,徐长航,等. 采掘工作面孕突过程地应力诱使煤体初始破坏动态响应机制[J]. 煤炭科学技术,2023,51(10):140−154.
  • Citation
    WANG Chaojie,TANG Zexiang,XU Changhang,et al. Dynamic response mechanism of initial failure of coal mass induced by in-situ stress in an outburst inoculation process of the working face for coal mining[J]. Coal Science and Technology,2023,51(10):140−154.
  • 相关专题
  • 图表
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    • 采动煤岩体孕突过程力学加卸载路径

    图(13) / 表(0)

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