Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources, China University of Mining and Technology-Beijing
School of Energy and Mining Engineering, China University of Mining and Technology-Beijing
Ministry of EmergencyManagement Key Laboratory for Prevention and Control of Coal Mine Disasters

冲击倾向性是煤的固有力学属性,也是评价煤矿冲击地压风险的重要依据。提出了一种基于针贯入法快速测定煤冲击倾向性的实验方法;结合纵波波速测试和单轴压缩实验,探究了具有不同贯入度指数的煤样对应的物理力学性质差异及在受压破坏过程中能量演化规律,采用剩余弹性应变能释放率指数 KRE,定量表征了弹性应变能累积释放特性并进行冲击倾向性评价。通过数据拟合与回归分析,获得了测试煤样贯入度指数与纵波波速、单轴抗压强度、弹性模量等物理力学参数的对应关系,并建立了贯入度指数和冲击能量指数、弹性能量指数、动态破坏时间、剩余弹性应变能释放率指数等冲击倾向性指标的关联表达式;构建了基于贯入度指数的煤冲击倾向性分级评价方法,采用对应煤样冲击倾向性测试时煤屑弹射质量比 F 对基于贯入度指数的煤冲击倾向性分级评价方法进行了验证。结果表明:煤的贯入度指数与纵波波速、单轴抗压强度、弹性模量等物理力学参数及冲击能量指数、弹性能量指数、剩余弹性应变能释放率指数等冲击倾向性指标呈幂函数正相关关系,与动态破坏时间呈负相关的指数关系;贯入度指数越大,煤的弹性变形和储能性能越强;贯入度指数为 85 N/mm 时是煤单轴抗压强度突变临界值;利用针贯入法测定煤的物理力学性质、弹性应变能储存释放特性及冲击倾向性具有良好的可行性与可靠性。

The bursting tendency is the inherent mechanical property of coal, and the important basis for evaluating the degree of coal bursting risk in underground coal mine. In this paper, an experimental method based on a needle penetrationtest for a rapid determination of coal bursting tendency was proposed. Combined with the needle penetration test, longitudinal wave velocity test and uniaxial compression experiment, the differences in the physical and mechanical properties ofcoal samples with different needle penetration indexes ( NPI ) and the energy evolution law during compression failurewere explored. The residual elastic energy release rate index KRE was used to quantitatively characterize the accumulationand release characteristics of elastic strain energy and evaluate the coal bursting tendency. Through data fitting and regression analysis, the corresponding relationships between NPI and the physical and mechanical parameters such as longitudinal wave velocity, uniaxial compressive strength, elastic modulus were obtained. The correlation expressions betweenNPI and the coal bursting tendency indexes such as bursting energy index, elastic strain energy index, dynamic failuretime, residual elastic energy release rate index were established. The classification of coal bursting tendency based on NPIwas proposed and validated using the ejection mass ratio of coal cuttings F. The results show that there is a power func-tion positive correlation between the NPI and the physical and mechanical parameters such as longitudinal wave velocity,uniaxial compressive strength, elastic modulus, and the coal bursting tendency indexes such as bursting energy index,elastic strain energy index, dynamic failure time, residual elastic energy release rate index. An exponential function negat-ive correlation was found between the NPI and the dynamic failure time. The larger the NPI is, the stronger the elastic de-formation and energy storage performance of coal. When the NPI is 85 N/mm, there is a sudden change in the uniaxialcompressive strength of coal. The needle penetration test is feasible and reliable in predicting the physical and mechanicalproperties, elastic strain energy storage and release characteristics and the bursting tendency of coal.

国家自然科学基金资助项目(52225402,U1910206)

赵毅鑫,谢镕澴,高艺瑞. 煤冲击倾向性的针贯入法测定[J]. 煤炭学报,2023,48(5):1932−1942.

ZHAO Yixin, XIE Ronghuan, GAO Yirui. Coal bursting tendency evaluation by needle penetration test[J].Journal of China Coal Society,2023,48(5):1932−1942.