罗生虎,王同,伍永平,等. 结构瞬变激励下采场煤岩的力学响应[J]. 煤炭学报,2023,48(12):4406−4416. doi: 10.13225/j.cnki.jccs.2023.0916
引用本文: 罗生虎,王同,伍永平,等. 结构瞬变激励下采场煤岩的力学响应[J]. 煤炭学报,2023,48(12):4406−4416. doi: 10.13225/j.cnki.jccs.2023.0916
LUO Shenghu,WANG Tong,WU Yongping,et al. Mechanical response of coal and rock in stope under transient excitation of structure[J]. Journal of China Coal Society,2023,48(12):4406−4416. doi: 10.13225/j.cnki.jccs.2023.0916
Citation: LUO Shenghu,WANG Tong,WU Yongping,et al. Mechanical response of coal and rock in stope under transient excitation of structure[J]. Journal of China Coal Society,2023,48(12):4406−4416. doi: 10.13225/j.cnki.jccs.2023.0916

结构瞬变激励下采场煤岩的力学响应

Mechanical response of coal and rock in stope under transient excitation of structure

  • 摘要: 煤岩动力灾害是深部矿井开采面临的主要灾害之一,揭示采场煤岩动力学响应的发生机理,是解决采场煤岩动力灾害的理论基础。采用理论分析、模拟实验和现场实测相结合的方法,研究覆岩空间结构瞬变激励作用下采场煤岩的动、静力学响应。结果显示:工作面形成后,覆岩发生变形破坏,破裂面以外、采动影响范围以内不同岩层组成的覆岩空间结构,是其影响范围内的采场煤岩产生不同力学响应的内因。回采过程中,坚硬岩层的破断等子系统的瞬时失稳,会造成覆岩空间结构大系统的瞬变,进而导致其影响范围内采场煤岩动态力学响应的发生和静态力学响应的阶变。在采场煤岩的动力学响应过程中,其动载是由震源区的震动和覆岩空间结构的瞬变共同引起的,其耗散的能量由震源区释放的应变能和覆岩空间结构释放的重力势能两部分构成;并且,采场煤岩的动力学响应具有区域性,远离瞬变区域的动力学响应不明显。受覆岩空间结构瞬变影响,瞬变前、后的平衡态时,其影响范围内采场煤岩的静态力学响应存在明显差异,工作面前方煤体上的支承压力峰值点前移,峰值减小,形成正、负阶变区。基于动静法,建立了一种覆岩空间结构瞬变过程中采场煤岩动−静载荷叠加的定量计算方法,最大动载量约为静态应力阶变量的2倍,工作面前方煤体上瞬时最大支承压力的峰值位置位于初始静载峰值的前方。

     

    Abstract: Dynamic disaster is one of the main disasters in deep coal mining. Revealing the response mechanism is the theoretical basis for solving dynamic disasters of coal-rock of stope. In this paper, the dynamic and static response of coal and rock under the action of structural transient excitation is studied by means of theoretical analysis, physical experiment and field measurement. Results show: The overlying strata is deformed and destroyed after the formation of working face. The spatial structure of overlying strata composed of different strata outside the fracture surface and within the influence range of mining is the internal cause of different mechanical responses of coal and rock in the stope within its influence range. The instability of subsystems such as the fracture of hard strata will cause the transient of spatial structure in the process of mining, which will lead to the occurrence of dynamic mechanical response of coal and rock in the stope and the step change of static mechanical response within its influence range. In the process of dynamic response of coal and rock in the stope, the dynamic load is caused by the vibration of the source area and the transient of the spatial structure. The dissipated energy is composed of two parts: the release of strain energy in the source area and the release of gravitational energy in the spatial structure. Moreover, the dynamic response of coal and rock in the stope is regional, and the dynamic response away from the structural transient region is not obvious. Due to the transient influence of the spatial structure of the overlying strata, the static mechanical response of the coal and rock in the stope is obviously different before and after the transient equilibrium state. Affected by this, the peak point of the abutment pressure on the coal before the working face moves forward, the peak value decreases, and the positive and negative step change zones are formed. Based on the dynamic and static mechanics method, a quantitative calculation method for the superposition of dynamic and static loads of coal and rock in the process of structural transient is established. The maximum dynamic load is about 2 times of the step variable of the static stress, and the peak position of instantaneous maximum abutment pressure on the coal before the working face is located in front of the initial static load. The results have certain theoretical reference value for the research and prevention and control of dynamic disasters in stope.

     

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