深部煤岩组合体整体破坏的非线性模型研究

Investigation on whole failure nonlinear model for deep coal-rock combined bodies

煤是一种复杂的地质体,其内部具有大量的微裂隙及孔隙。煤岩组合体中,岩石为较硬的部分,煤及其内部微裂隙、孔隙及岩-煤之间的界面共同组成较软的部分。根据工程应变和自然应变(真实应变),建立了表征煤岩组合体的非线性理论模型。该理论模型与煤岩组合体的单轴压缩试验数据吻合度较好。对该理论模型进行简化并对参数进行了讨论,发现参数a约等于1;参数b、参数c与煤样尺寸、弹性模量有关,参数b越大,非线性段逐渐延长,且增大速率基本保持不变;参数c越大,非线性段同样逐渐增长,但是增大速率逐渐减小,并且随着轴向荷载的增加,线性段逐渐重合。

Coal is a kind of complex geological body with a large number of cracks and pores. In the coal-rock combined bodies,rocks are the hard part and coal and its internal cracks,pores and the interface between coal and rock are put together to be the soft parts. According to the engineering strain and natural strain,a nonlinear theoretical model has been built to characterize the coal-rock combined bodies. This nonlinear theoretical model generally matches well with the uniaxial compression testing data. Then parameters are discussed by the simplified model and finding that,a is approximately equal to 1,b and c are the parameters that associated with size,elastic modulus of coal. Parameter b extends gradually in the nonlinear phase and the incremental rate basically remains unchanged. Parameter c also goes up increasingly in the nonlinear phase. The incremental rate decreases with a gradual overlap trend in the linear phase when the axial load increases.