摘要
动力扰动促使煤岩破坏失稳是其导致煤岩动力灾害事故频发的主要原因,分析外界扰动对煤岩稳定性的影响对灾害的预测与防治具有重要意义。利用大型振动试验装置和自振频率测试系统,对煤岩体在底板扰动破坏情况下自振频率的变化特征及其与稳定性的关系进行了研究。结果表明:在振动影响作用下,煤岩体裂隙扩展,损伤程度加大,造成刚度系数的降低和阻尼比系数的上升,进而导致试件整体自振频率呈现下降趋势,且下降的速率与动力扰动的加速度和频率密切相关,并出现煤岩结构体与其中煤体分层自振频率不一致的现象。根据试验结果从调整扰动源和煤岩体两个角度提出了防止或减弱动力扰动对煤岩动力灾害诱发影响的合理化建议。
It is ease for dynamic disturbance to induce coal and rock damage and instability,which would result in the frequent occurrences of dynamic disaster.Thus,the research on the effect of disturbances on coal and rock stability is vital to disaster prediction and prevention. By using the vibration experimental device and natural frequency test system,the change characteristics of natural frequency under the condition of bottom disturbance were investigated.Moreover,the relationship between the change characteristics and rock stability was also investigated.It is demonstrated that under the vibration,fracture extension and increasing damage degree appear. It causes the decline of stiffness coefficients and the rise of damping coefficients,and then the natural frequency of the whole specimen presents a downward trend.Simultaneously,it is discovered that the declining rate is closely related to the acceleration and frequency of the external dynamic disturbance,and natural frequencies of structure and coal are inconsistent Based on the results,the reasonable suggestions from the points of adjusting the disturbance source and the coal and rock are proposed.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2015年第10期2422-2429,共8页
Journal of China Coal Society
基金
国家自然科学基金资助项目(51274206)
国家自然科学青年基金资助项目(51404277)
中央高校基本业务费专项资金资助项目(2014QZ05)
关键词
煤岩
振动
自振频率
动力扰动
coal and rock
vibration
natural frequency
dynamic disturbance
