煤层冲击倾向性指标体系研究及实验验证  

A Research on the Index System and Its Experimental Verification of the Coal Seam Impact Tendency

作　　者：张天军[1] 包若羽 王乾[1] 羽玥 Zhang Tianjun;Bao Ruoyu;Wang Qian;Yu Yue(College of Sciences,Xi’an University of Science and Technology,Xi’an 710054,China;College of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]西安科技大学理学院,陕西西安710054 [2]西安科技大学安全科学与工程学院,陕西西安710054

出　　处：《湖南科技大学学报（自然科学版）》2019年第3期1-10,共10页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家自然科学基金资助项目(51374168;51374236;51604214)

摘　　要：针对传统煤层冲击倾向性指标存在的局限性,基于考虑残余强度的损伤统计本构模型,从损伤因子、损伤速率和损伤速率加速度3个角度分别研究峰值强度点、损伤速率最值点、损伤速率加速度最值点处的损伤规律,对残余强度和动态损伤应变进行了修正,提出了新的煤层冲击倾向性指标—盈余能指数变化率,建立冲击倾向性指标体系,并开展冲击倾向性实验对新指标体系合理性进行验证.结果表明:考虑残余强度的损伤统计本构模型能较好地反映煤岩体峰值强度后应力—应变曲线变化趋势及残余强度特点,得到峰值强度点、损伤速率最值点和损伤速率加速度最值点处的损伤规律及损伤速率最大值表达式;根据修正后动态损伤应变的力学意义得到动态损伤应变与动态破坏时间关系式,采用动态损伤应变来表征动态破坏时间,从而使冲击倾向性实验不再受加载方式的限制;采用盈余能指数变化率指标可综合衡量盈余能、峰后破坏过程损耗应变能、动态破坏时间的变化情况;由最大损伤速率、动态损伤应变、盈余能指数变化率构成的新冲击倾向性指标体系更为有效和全面,为准确评价煤层冲击倾向性工作提供新方法.The damage law of the peak intensity point,the maximum value of the damage rate and the maximum value of the damage rate acceleration were studied respectively from the three angles of damage factor,damage rate and damage rate acceleration on the basis of the constitutive model of damage statistics of the residual strength for the limitation of the traditional impact tendency index of coal and rock mass;the residual strength and dynamic strain were corrected;the change trend of the surplus energy index,which was the new coal seam impact tendency,was put forward;the index system of the impact tendency was established;the impact tendency experiments were verified the rationality of the new index system.The results show that the constitutive model of the residual strength of the damage statistics can truly reflect the post-stress,the trend of stress-strain curve and the residual strength;the damage law and the maximum expressions of damage rate at the peak intensity point,the maximum value of the damage rate and the maximum value of the damage rate acceleration are obtained;the relationship between the dynamic damage strain and the dynamic damage time is obtained according to the mechanical significance of the corrected dynamic damage strain;the dynamic damage time is used to characterize the dynamic failure time so that the impact tendency experiment is no longer limited by the loading methods;the change rate of the surplus energy index can comprehensively measure the variation of the surplus energy,the plastic deformation energy,and the dynamic damage time;the new impact tendency index system consisting of the maximum value of the damage rate,dynamic damage strain,and the change rate index of the surplus energy,is more effective and comprehensive and will provide a new approach to evaluate the coal seam impact tendency.

关 键 词：冲击倾向性 损伤统计本构模型 最大损伤速率 动态损伤应变 盈余能指数变化率 

分 类 号：TD324.1[矿业工程—矿井建设]