张传玖,任建慧,李宣良,等. 冲击倾向性对煤体动力学特性影响研究[J]. 中国矿业,xxxx,x(x):1-8. DOI: 10.12075/j.issn.1004-4051.20230210
    引用本文: 张传玖,任建慧,李宣良,等. 冲击倾向性对煤体动力学特性影响研究[J]. 中国矿业,xxxx,x(x):1-8. DOI: 10.12075/j.issn.1004-4051.20230210
    ZHANG Chuanjiu,REN Jianhui,LI Xuanliang,et al. Study on the influence of bursting liability on coal dynamic characteristics[J]. China Mining Magazine,xxxx,x(x):1-8. DOI: 10.12075/j.issn.1004-4051.20230210
    Citation: ZHANG Chuanjiu,REN Jianhui,LI Xuanliang,et al. Study on the influence of bursting liability on coal dynamic characteristics[J]. China Mining Magazine,xxxx,x(x):1-8. DOI: 10.12075/j.issn.1004-4051.20230210

    冲击倾向性对煤体动力学特性影响研究

    Study on the influence of bursting liability on coal dynamic characteristics

    • 摘要: 煤体动力学特性研究对于探明煤炭地下开采过程中冲击地压形成机制起着关键作用。为了探明冲击倾向性对煤体动力学特性的影响,本文对三种煤试件进行单轴变应力上限循环加卸载试验及冲击动力学试验。试验结果表明:经过变应力上限循环加卸载试验后三种煤试件应变能Uen与对应输入能Uinn之间均存在线性函数关系。同时测定以上三种煤试件剩余弹性能指数CEF分别为25.35 kJ/m3、30.34 kJ/m3与33.26 kJ/m3,表明屯宝煤矿煤试件及雨田煤矿煤试件具有强冲击倾向性,布尔台煤矿煤试件具有弱冲击倾向性;与之对应的煤体经SHPB试验后动态抗压强度分别增大了1.32倍、1.40倍及1.45倍,动态弹性模量分别增大1.21倍、1.34倍及1.39倍,破坏变形分别增大了1.34倍、1.47倍与1.53倍,即随着剩余弹性能指数的增加,煤体动力学参量增长倍数逐渐增大,表明煤体冲击倾向性越大,其冲击动力学相关参数较静力学状态下参量提高越多。随着冲击倾向性的增加,煤体经动载崩裂后的碎块平均等效直径不断降低,破碎分形维数不断变大,表明冲击倾向性较大的煤体受冲击载荷作用后崩解的更加复杂破碎,动力学响应变得更加显著。

       

      Abstract: The study of coal dynamic characteristics plays a key role in exploring the formation mechanism of rock burst during underground coal mining. In order to explore the impact of bursting liability on the coal dynamic characteristics, uniaxial cyclic loading and unloading tests and impact dynamics tests are carried out on three types of coal specimens. The test results show that there is a linear function relationship between the strain energy Uen and the corresponding input energy Uinn of the three types of coal after cyclic loading and unloading test with variable stress upper limit. Meanwhile, the index of residual elastic energy CEF of the above three types of coal is 25.35 kJ/m3, 30.34 kJ/m3 and 33.26 kJ/m3, respectively, indicating that the coal specimens of Tunbao Coal Mine and Yutian Coal Mine have strong bursting potential, while the coal specimens of Buertai Coal Mine have weak bursting potential. After SHPB test, the dynamic compressive strength of the corresponding coal increases by 1.32, 1.40 and 1.45 times, the dynamic elastic modulus increases by 1.21, 1.34 and 1.39 times, and the failure deformation increases by 1.34, 1.47 and 1.53 times, respectively. That is, with the increase of the index of residual elastic energy, the growth factor of coal dynamic parameters gradually increases, indicating that the larger the coal bursting liability is, the more the parameters related to the impact dynamics increase compared with the static state. With the increase of the bursting liability, the average equivalent diameter of the fragments after the coal collapse under dynamic load keeps decreasing, and the fractal dimension of the fragmentation keeps increasing, which indicates that the coal with large bursting liability is more complicated and broken after the impact load, and the dynamic response becomes more significant.

       

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