基于分形理论的岩石裂隙非线性渗流各向异性研究

针对裂隙岩体非达西渗流问题，开展了不同粗糙裂隙非线性渗流特性的研究。将完整的方形岩块采用劈裂法制成裂隙试件，用三维光学扫描系统量测裂隙表面形貌，并采用Kulatilake提出的自仿射分形维度方法计算表面的分形维度来表征粗糙表面的各向异性特征。根据裂隙流的曲折效应，在Forchheimer定律基础上，提出了水文弯曲度和表面分形幂律关系来表征非线性特点，并由此提出了新的粗糙裂隙非线性分形模型。对各组裂隙试件在2个方向（0°，90°）上进行饱和渗流试验，发现流动符合Forchheimer定律且存在各向异性特点，最后由分形模型，提出了区分达西流与Forchheimer流的新判据。

Study on non-linear flow anisotropy behavior in rough rock fractures based on fractal theory

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.