基于损伤统计本构模型的煤层冲击倾向性研究

针对目前国内煤层冲击倾向性指标存在的问题，基于煤岩应变强度理论、煤岩微元强度服从Weibull随机统计分布的假设和连续介质损伤力学理论，采用单轴压缩下煤岩损伤统计本构模型，用最优化方法确定该模型的关键参数，同时分析了各参数的物理意义，进而给出了冲击能指数和弹性能指数的理论计算方法，并提出了最大损伤速率和反应动态破坏时间的动态损伤应变新指标。数值试验和现场试验结果表明：采用最优化方法确定该模型参数能更好地拟合煤岩应力-应变全过程曲线；修正后与新提出的冲击倾向性指标理论计算方法合理可行，物理意义明确，能很好地反映煤层的冲击倾向性，为深入研究煤层冲击倾向性的本质提供了一种新的思路。

Bursting liability of coal based on damage statistical constitutive model

Aiming at the problem of domestic bursting liability of coal at present,a statistical constitutive model for coal rock damage under uniaxial compression was adopted based on the strain strength theory,the strength of coal rock micro unit with Weibull random statistical distribution hypothesis and the continuum damage mechanics theory.The key parameters of the model were determined according to the optimization method,and the physical meanings of parameters were analyzed.Furthermore,the theoretical calculation methods of bursting energy index and elastic strain energy index were presented,and the new indexes of maximal damage rate and strain of dynamic fracture which could reflect the duration of dynamic fracture were proposed.According to the numerical and field experiment,some results show that the statistical constitutive model whose parameters determined by the optimization method can fit the complete stress strain curve of coal rock better;the theoretical calculation methods of new and modified indexes for bursting liability indexes are reasonable and feasible,and the physical meanings are clear,thus,they can excellently reflect the bursting liability of coal.It provides a new approach to further study the essence of bursting liability of coal.