在岩石爆破理论的基础上分析了煤体中爆炸应力波的作用机理,借助损伤力学理论探讨了煤体在爆炸应力波作用下的损伤断裂准则。煤体中爆炸应力波传播与衰减规律模拟实验结果表明:煤体中爆炸应力波一般包含2段波形,第1段由压缩相和拉伸相组成简单波形,第2段是由多种作用形成的复杂波形;爆炸应力波作用下,煤体首先承受压应力,而后承受拉应力,且压缩相的作用时间较拉伸相作用时间短;煤体中爆炸应力波的衰减速度较一般岩体中的快,实验条件下应力波衰减因数符合α=3-μ/(1-μ),爆炸应力波的主要作用是在煤体中形成少量新裂隙、激活煤体中原生裂隙并打破煤体中瓦斯气体的平衡状态。
Based on the theory of rock blasting,the action mechanism of explosion stress wave in coal was analyzed.The damage fracture criteria for coal subjected to explosion stress wave was explored according to the damage mechanics theory.And,simulation experiments were conducted to obtain the attenuation law of explosion stress wave propagation in coal.The experimental results show that the stress wave at each measured point contains two or more waveforms,there are compression phase and tensile phase in the first wave,the waveform of which is simple and smooth,and the second wave is the result of a variety of action,the waveform of which is complex;that the coal media is first under compressive stress and then under tensile stress,the action time of the compressive stress was shorter than that of the tensile stress;and that the decay rate of explosion stress wave in coal is faster than in general rock.The main effects of explosion stress wave in coal consist of forming a small number of new crannies,activating the native cranny,and breaking the balance of coal gas.