低加载率范围内煤岩组合体冲击倾向性的率效应试验研究

发布时间：2018-03-22 14:18

本文选题：冲击地压　切入点：煤岩组合体　出处：《煤炭学报》2017年11期 　论文类型：期刊论文

【摘要】：以煤岩组合体为研究对象,进行4种不同量级下的低加载率(10-3~100MPa/s)单轴压缩试验,以抗压强度、弹性模量、冲击能量指数、弹性能量指数、归一化动态破坏时间为参量,考察加载率对煤岩组合体冲击倾向性的影响。研究结果表明:随着加载率的提高,煤岩组合体的承载失效结构由煤体转化为煤岩组合体,并存在明显的临界加载率现象。煤岩组合体的抗压强度和弹性模量在临界加载率以下保持在较低值,在临界加载率以上保持在较高值;冲击能量指数随着加载率的提高先增加后减小,在临界加载率附近出现最大值;弹性能量指数随着加载率增加而提高;修正动态破坏时间在临界加载率之前降低幅度较快,在临界加载率之后缓慢下降然后趋于平稳;综合判断煤岩组合体的冲击倾向性随加载率的增加划分为两个比较明显的水平,并且在临界加载率附近表现出较为明显的冲击倾向性突变。临界加载率效应可为现场条件下确定合适的工作面推进速度提供参考。
[Abstract]:Taking coal and rock assemblage as research object, the uniaxial compression tests with low loading rate of 10 ~ (-3) ~ (10 ~ (-3)) ~ (100) MPA / s were carried out under different orders of magnitude. The compressive strength, elastic modulus, impact energy index, elastic energy index and normalized dynamic failure time were taken as parameters. The effect of loading rate on the impact tendency of coal-rock assemblage is investigated. The results show that with the increase of loading rate, the load-bearing failure structure of coal-rock assemblage changes from coal to coal-rock assemblage. The compressive strength and elastic modulus of the coal and rock assemblage are kept below the critical loading rate at a lower value and above the critical loading rate at a higher value. With the increase of loading rate, the impact energy index first increases and then decreases, and the maximum appears near the critical loading rate; the elastic energy index increases with the increase of loading rate; the modified dynamic failure time decreases rapidly before the critical loading rate. The impact tendency of coal and rock assemblage is divided into two distinct levels with the increase of loading rate. The critical loading rate effect can provide a reference for determining the suitable working face advance speed under the field conditions.
【作者单位】：中南大学资源与安全工程学院;中国矿业大学煤炭资源与安全开采国家重点实验室;中南大学高等研究中心;
【基金】：中国矿业大学煤炭资源与安全开采国家重点实验室开放研究基金资助项目(13KF06)
【分类号】：TD324

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