关键词: 岩石裂隙, 非线性渗流, 分形维度, Forchheimer定律, 各向异性, 临界雷诺数

Abstract: Aiming at the issue of Non-Darcy seepage flow in fracture, the seepage characteristics in different rough fractures were studied . The test speciment of fracture rock mass were obtained by splitting the integrated cubic rock mass, and the fracture surface topographies of rock mass were measured by stereotopometric scanning system. Surface roughness anisotropy was quantified by self-affine fractal dimension D using measured data. According to tortuosity effect of flow in fracture, the non-linear flow was characterized by a power law relationship of hydraulic tortuosity and fractal dimension based on Forchheimer law. Fracture seepage tests were conducted from two incidence directions (0°and 90°). The results showed that non-linear flow with anisotropy could be well described by Forchheimer law. Finally, a new formula was proposed, which can distinguish the linear flow and Forchheimer flow.

Key words: fracture, non-linear flow, fractal dimension, Forchheimer law, anisotropy, critical Reynolds number