摘要
冲击地压一定是在能量驱使下发生的,为探索引发冲击地压的能量在煤岩系统中的积聚层位,构建了煤岩组合体力学模型,推导了煤岩组合体峰前能量分布公式,对细砂岩-煤(finesandstone-coal,简称FC)、粗砂岩-煤(gritstone-coal,简称GC)、细砂岩-煤-粗砂岩(fine sandstone-coal-gritstone,简称FCG)3种组合体开展5种加载速率下的能量积聚规律试验,分析了组合体破坏特征、力学特性及能量积聚规律。试验表明:(1)在0.001mm/s加载速率下,组合体峰前能量主要以原生裂纹的扩展、贯通的形式缓慢耗散,属于塑性完全破坏;在0.1mm/s加载速率下,组合体峰前能量主要以局部弹射破坏的形式快速释放,属于脆性不完全破坏。(2)组合体的抗压强度、弹性模量、峰前能量、冲击能量指数与加载速率呈对数关系。随着加载速率增大,组合体抗压强度、弹性模量、冲击能量指数增幅逐渐减小,峰前能量增长率呈现低-高-低的趋势。(3)随着加载速率增加,煤组分储能增多,能量占比增大。在0.001~0.010mm/s加载速率下,煤组分积聚能量增加较快;在0.010~0.100 mm/s加载速率下,煤组分积聚能量增加较慢。(4)相同加载速率下,煤组分能量占比顺序:FC组合体>FCG组合体>GC组合体。(5)组合体中煤组分能量占比均大于50%,煤组分是能量积聚的主要载体。相同应力条件下,软弱岩层能量积聚能力强于坚硬岩层,更易积聚能量。研究结果可为确定冲击地压能量积聚层位和释能减冲工作提供参考。
Rockburst must occur under the drive of energy. In this study, a mechanical model of coal-rock combined body was constructed to explore the accumulation layer of energy causing rockburst in coal-rock system, and a formula of pre-peak energy distribution of coal-rock combined body was deduced. The experiments of energy accumulation under five loading rates of fine sandstone-coal(FC), coarse sandstone-coal(GC) and fine sandstone-coal-coarse sandstone(FCG) were carried out. The failure characteristics, mechanical properties and energy accumulation law of the combined body were analyzed. The results showed that: 1)At a loading rate of 0.001 mm/s, the pre-peak energy of the combined body was mainly dissipated slowly in the form of primary crack propagation and coalescence, which belongs to complete plastic failure;and at the 0.1 mm/s loading rate, the pre-peak energy of the combined body was mainly released rapidly in the form of local ejection failure, which belongs to brittle incomplete failure. 2) The compressive strength, elastic modulus, pre-peak energy and impact energy index of the combined body have a logarithmic relationship with the loading rate. As the loading rate increases, the increases of compressive strength, elastic modulus and impact energy index decrease gradually, and the pre-peak energy growth rate shows a "low-high-low" trend. 3) The energy storage and energy share of coal components increase as the loading rate increases. At the 0.001-0.010 mm/s loading rate, the accumulated energy of coal components increases rapidly and at the 0.010-0.100 mm/s loading rate, the accumulated energy of coal components increases slowly. 4) At the same loading rate, the energy proportion of coal components is in the following order: FC combined body > FCG combined body > GC combined body. 5) The energy proportion of coal component in the combined body surpasses 50%,and the coal component is the main carrier of energy accumulation. Under the same stress condition, the energy accumulation ability of weak rock is stronger than that of hard rock. In other words, energy is more easily accumulated in weak rocks. The research results can provide an insight into determining the energy accumulation layer of rock burst and the work of energy release and impact reduction.
作者
陈光波
张俊文
贺永亮
张国华
李谭
CHEN Guang-bo;ZHANG Jun-wen;HE Yong-liang;ZHANG Guo-hua;LI Tan(Mining Research Institute,Inner Mongolia University of Science and Technology,Baotou,Inner Mongolian 014010,China;School of Energy and Mining Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Mines,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Institute of Mining Engineering,Heilongjiang University of Science and Technology,Harbin,Heilongjiang 150022,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2022年第S02期130-143,154,共15页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51774122)
内蒙古自治区自然科学基金项目(No.2020BS05007)
越崎杰出学者资助项目(No.2020JCB01)。
关键词
冲击地压
煤岩组合体
加载速率
力学特性
峰前能量
能量积聚
rock burst
coal-rock combined body
loading rate
mechanical properties
pre-peak energy
energy accumulation
