Permiability of a fractal single fracture under the coupling of multiple experimental cases
It is of great significance to explore the seepage characteristics of fractured rock masses in engineering fields such as resource mining (e.g., unconventional gas, oil and gas), the stability of geotechnical engineering and geological engineering. In order to explore the seepage characteristics of fractal single-fracture under the coupling conditions of different pressure heads h, mechanical gap widths e and fractal dimensions D, the three-dimensional physical models of the fractal single-fracture were constructed based on the Weierstrass-Mandelbrot function and 3D printing technology. The results show that, (1) the seepage laws of fracture show clear differences under different coupling conditions; (2) the seepage state consists of three types of conditions, namely, laminar flow, the laminar flow to laminar-turbulent transition interval, and the laminar-turbulent transition interval, with differences in the corresponding experimental conditions when the seepage state changes; (3) with increasing D, the fracture permeability decreases. The increase of h promotes the decrease of permeability, and with h increasing by four times, the seepage flow decreases by 1.53 times. With the increase of e, an increasing fractal dimension leads to the percentage of flow reduction decreasing from 81.50% to 19.18%, indicating that the increase of e inhibits the decreasing trend of the permeability.