中文摘要：

地下工程中的破碎岩石在渗流过程中其结构发生两方面变化,一方面由于水压的作用引起孔隙结构发生变化,另一方面固体材料之间的接触应力造成棱角破损。因此,承压破碎岩石的渗流不同于自然堆放状态下的堆石渗流,其渗透特性随着位移或载荷的变化而产生显著变化。基于MTS815.02型岩石力学试验系统及破碎岩石渗透仪,利用稳态渗透法及轴向位移控制法测定了粒径分别为5mm―10mm、10mm―15mm、15mm―20mm、20mm―25mm以及混合粒径的破碎砂岩、煤矸石及灰岩在承压过程中非Darcy流的渗透特性,给出了岩样在不同轴向位移水平下的孔压梯度与渗流速度关系曲线,得到了渗透特性随孔隙率的变化规律,揭示了Darcy流偏离因子可能为负的现象。研究表明：1）随着孔隙率的减少,渗透率呈现整体下降的趋势,而Darcy流偏离因子的绝对值呈现整体上升的趋势;2）破碎岩石的渗透性不仅和外载水平及当前孔隙度有关,还与碎石的粒径、颗粒的排列方式以及初始孔隙结构（如初始孔隙通道）等有关;3）三种破碎岩石渗透率的量级为10^-16m^2―10^-12m^2,Darcy流偏离因子的量级为10^12kg/m^4―10^15kg/m^4;4）当颗粒的破碎细化现象严重时,Darcy流偏离因子出现负值的可能性较大。

英文摘要：

In the underground engineering, there are two changes that will take place in the structure of the broken rock during the seepage： One is the variation in pore structure caused by water pressure; another is the breaking of the edges and corners caused by the contacting stresses between the solid grains. Thus the flow in broken rock is different from the one in rock-fills packed up naturally, and its permeating properties change greatly with the displacement or the load. In this paper, the MTS815.02 Rock Mechanics Test System together with a seepage instrument is used to test the seepage properties of non-Darcy flow in the broken sandstone, coal gangue and limestone with the grain sizes 5mm-10mm, 10mm-15mm, 15mm-20mm, 20mm-25mm and the mixed grain size by the method of steady permeating and the method of controlling the axial displacements. By the experiments, the relation curves of the pore pressure gradient and the seepage velocity corresponding to the variant axial displacement of the rock samples are obtained; furthermore the rules of the permeating properties varying with porosity are acquired. The experimental results indicate that the coefficient of deviating from Darcy-flow may be negative. Some conclusions can be drawn as follows： 1） In a general trend, the permeability declines while the absolute value of the coefficient of deviating from Darcy-flow increases with the decreasing of the porosity; 2） The permeability is related with the loading level, the present porosity, the grain size, the construction style of the grains and the initial pore structure; 3） The magnitude of the permeability for the three kinds broken rock is 10^-16m^2-10^-12m^2 and the magnitude of deviating coefficient is 10^12kg/m^4- 10^15kg/m^4：4） when the breaking of the grains is very serious, the coefficient of deviating from Darcy-flow may be negative very possibly.