考虑尺度效应的煤样渗透率对围压敏感性试验研究

通过试验研究了不同尺度(d=2.5,3.8,10 cm）煤样在围压加、卸载条件下的渗透率变化.对试验结果进行非线性拟合分析，得出煤样的渗透率与围压之间存在负指数关系.煤样渗透率对围压敏感性存在着尺度效应，即小尺度煤样在围压加卸载条件下(d=2.5 cm）渗透率变化比大尺度煤样（d=10 cm）更为敏感.煤样渗透率对围压敏感性的尺度效应在围压加、卸载过程中呈现出不同的特点.在围压加载初期，尺度效应明显.随着围压增大，尺度效应减弱，卸载过程与此相反.推导了基于尺度效应的煤样渗透率对围压敏感性的计算公式，并对公式应用范围进行界定.

Experimental research on sensibility of permeability of coal samples under confining pressure status based on scale effect

The variation law of permeability of different scale coal samples(d=2.5,3.8,10 cm) under confining pressure load-on /load-off status was researched based on the experiment.After nonlinear fitting to experimental results,established the mathematic relationship of permeability and confining pressure.The scale effect of stress sensibility of permeability of coal samples to confining pressure status was found by the experiment.The change of permeability about smaller scale coal samples(d=2.5 cm) was more sensitive than the larger one's(d=10 cm).The scale effect of stress sensibility of permeability of coal samples under confining pressure status has different features.At the initial stage of confining pressure load,scale effect is obvious.With the increase of confining pressure,scale effect turns weak.Scale effect of stress sensibility of permeability of coal samples under confining pressure unloading process is opposite to loading process.The formula of stress sensitivity of coal samples concerning scale effect and its application range were deduced.