破断岩体裂隙的流体流动特性分析

讨论立方定律成立的前提条件，指出立方定律只有在裂隙隙宽波动极小的情况下才能近似成立，对于岩体粗糙裂隙来说，此种状态只会出现在裂隙的局部区域，即局部立方定律；而在裂隙隙宽波动较大的区域，则需准确表述裂隙粗糙对流体流动的影响作用。提出天然粗糙裂隙的多平行板离散等效模型，可以有效地适用局部立方定律，推导粗糙裂隙的隙宽表示和流量计算公式；借助数值软件分析隙宽波动对等效模型单元体内部流体压力的作用规律，并定义一个过量压力降损耗系数，基于该系数对粗糙裂隙的流量计算方法进行修正。

ANALYSIS OF PROPERTIES OF FLUID FLOW IN ROCK FRACTURES

This paper discuss the conditions for applicability of cubic law，it is pointed out that the cubic law express with average aperture is approximately valid only at the case of fracture with very small fluctuations in apertures. For rock fractures，such condition only appears in the local segment of rock fracture，which is the local cubic law. And in the regions of apertures with big fluctuations，the influence of geometric roughness on flow should be considered. For easily using the local cubic law，a series-parallel discrete equivalent model for natural rough fractures is introduced；and the equivalent aperture and flow formula of rough fracture are derived. Variation analysis of fluid pressure in equivalent model unit caused by big-aperture-fluctuation is carried out with numerical software；and then an excess pressure loss coefficient is defined to modify the calculation method of rough fractures flow.