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为分析饱水时间对煤体的力学性质与冲击倾向性指标的影响,对千秋煤矿2#煤层自然和饱水7~28 d处理后煤样,在RMT–150B岩石力学试验系统进行冲击倾向性指标测定。结果表明:在自然与饱水状态下,煤样的抗压强度与弹性模量、峰前积蓄能量和冲击能量指数均成正相关。饱水煤样的抗压强度、弹性模量、冲击能量指数以及峰前积蓄能量均有不同程度降低。饱水7~10 d后煤的力学性质和冲击倾向性指标变化显著,而后有所减缓。在自然含水状态下,2#煤层属于中等冲击类(II类),饱水7~28 d后2#煤层的冲击倾向性指标有较大降低,由中等冲击类变为弱冲击类(弱II类);建议千秋煤矿采煤工作面注水超前时间7~10 d,超前距离约30 m为宜。
In order to analyze the influence of water saturation time on the mechanical properties and impact propensity index of coal body, the coal seam samples of natural and saturated 7 ~ 28 d coal seam of Qianqiu Coal Mine were subjected to impact propensity Index determination. The results show that under natural and saturated conditions, the compressive strength of coal samples is positively correlated with elastic modulus, energy before storage and impact energy index. The compressive strength, elastic modulus, impact energy index and energy accumulated before the peak in the water-saturated coal samples all decreased to some extent. After 7 ~ 10 d of full water, the mechanical properties and impact propensity index of coal changed significantly, and then slowed down. Under the natural water condition, coal seam 2 # belongs to moderate impact type (II class), and the impact propensity index of coal seam # 2 decreases greatly after 7 ~ 28 days of full water flow, from moderate to weak impact type (weak II Class); recommended Qianqiu coal mining face water ahead of time 7 ~ 10 d, ahead of about 30 m is appropriate.