裂纹起裂规律对煤岩体破裂行为的影响

Influence of crack initiation law to fracture behavior of coal and rock mass

为获得压缩状态下含不同类型裂纹的煤岩体破裂行为,基于断裂力学分析张开型裂纹和闭合裂纹的起裂规律,研究裂纹类型对煤岩体抗破裂能力的影响.研究结果表明：几何参数及荷载对裂纹起裂规律的影响显著,含不同类型裂纹的煤岩体破裂特点相异.煤岩体含裂纹倾角越接近40~60o,长度越长,侧压系数越小,张开型裂纹曲率半径越大,闭合裂纹裂纹面摩擦系数越小,裂纹起裂应力越小,煤岩体也越易破裂,据此,提出了根据裂纹类型估算煤岩体破裂难易程度的方法.

In order to obtain coal and rock fracture behavior of different types crack under the compression state, this paper studied the influence of crack types to fracture resistance ability of coal and rock, and analyzed the initiation law of opening type crack and closed type crack based on fracture mechanics. The results show that the geometric parameters and load affect the initiation law of crack significantly. The characteristics of coal and rock fracture including different types of crack are different. The closer crack angle of coal and rock gets to 40 ~ 60 degree, the longer the length, and the smaller the coefficient of lateral pressure, the greater curvature radius of open type crack. The smaller crack surface friction coefficient of closed type crack, the smaller fracture stress of crack,and the easier the coal and rock burst. The method for estimating degree of coal and rock burst is put forward according to the types of crack based on the research results.