受载煤岩组合体破坏前能量分布规律

Law of energy distribution before failure of a loaded coal-rock combined body

为研究引发冲击地压的能量在煤岩系统中的分布规律,理论分析了二元、三元组合模型峰前能量分布计算公式,并对自主构建的不同比例的二元、三元组合体开展了轴向加载试验。试验结果表明:随着煤岩高度比增大,组合体峰前总能量也逐渐增大,但增幅逐渐减小;相同煤岩高度比的组合体,岩石组分越硬,组合体峰前总能量越小;无论何种组合体,煤组分能量占比最大,均大于50%;随着煤岩高度比的增大,煤组分能量占比逐渐增大,岩石组分能量占比逐渐减小;煤岩高度比相同的组合体,岩石组分越硬,煤组分能量占比越大。组合体峰前能量主要分布在煤组分中,其次为粗砂岩,细砂岩积聚能量最少。由此表明:煤岩系统中的能量主要分布在软弱煤岩层中,岩层弹性模量越大,积聚能量越少。据此提出了直接释能和间接释能两种冲击地压防控理念,对现场冲击地压的防治具有指导意义。

To study the distribution law of the energy that induced rockburst in a coal rock system,the calculation formula of pre-peak energy distribution of binary and ternary combined models was theoretically analyzed.The axial loading experiments of binary and ternary self-constructed combined bodies with different proportions were carried out.The experimental results show that with the increase of coal-rock height ratio,the pre-peak total energy increases,but the increase amplitude decreases gradually.For combined bodies with the same coal-rock height ratio,the harder the rock component is,the smaller the pre-peak total energy will be.Independent of coal-rock height ratios,the proportion of energy stored in the coal component is always higher,which is more than 50%.With the increase of coal-rock height ratio,the proportion of energy stored in the coal component increases gradually,and the proportion of energy stored in the rock component decreases gradually.For combined body with the same coal-rock height ratio,the harder the rock component is,the higher the proportion of energy stored in the coal component will be.The pre-peak energy of a combined body is mainly distributed in the coal component,followed by the gritstone,and the fine sandstone has the least accumulated energy.This shows that the energy in a coal-rock system is mainly distributed in the weak coal-rock strata,the greater the elastic modulus of a rock,the less the amount of accumulated energy.Based on this,two concepts of prevention and control of rock burst,direct release of energy and indirect release of energy,were put forward.The results are of guiding significance to the prevention and control of rock burst in the field.