A novel model is proposed to simulate radon migration by combining the fractal theory and the discrete fracture network (DFN) model. In the model, a power-law distribution based on fractal theory is applied to fracture length and aperture and the fracture locations and orientations are modeled with the Poisson distribution and von Mises-Fisher distribution, respectively. The model was applied to produce a computer code that can calculate the radon concentration, flux, and diffusivity of the fractured media. The key issues related to the model were analyzed and the results reveal that: (1) the threshold value of the ratio of the minimum fracture length to the maximum decreases as the fractal dimension of the fracture lengths and the relation between them follows an exponential law; (2) As the fractal dimension of the fracture lengths increases, more connected fractures are generated, resulting in a linear increase of the mean efficient radon diffusivity. (3) The dip angle is the parameter that has the greatest influence on radon migration in determining fracture orientations. (4) The radon exhalation rate increases exponentially with increasing advection velocity. (5) Models with larger fractal dimension for fracture lengths have larger representative elementary volume (REV) size and follow an exponential law.

结合分形理论和离散断裂网络模型，提出了一种模拟ra迁移的新模型。在该模型中，将基于分形理论的幂律分布应用于裂缝的长度和孔径，并分别利用泊松分布和冯·米塞斯·费舍尔分布对裂缝的位置和方向进行建模。应用该模型生成计算机代码，该计算机代码可以计算裂缝介质的the浓度，通量和扩散率。分析了与模型相关的关键问题，结果表明：（1）最小断裂长度与最大断裂长度之比的阈值随断裂长度的分形维数和它们之间的关系遵循指数律而减小; （2）随着断裂长度的分形维数的增加，产生更多的连通裂缝，导致平均有效ra扩散率线性增加。（3）倾角是确定fracture裂方向时对migration迁移影响最大的参数。（4）ad的呼出率随对流速度的增加呈指数增加。（5）对于裂缝长度而言，具有较大分形维数的模型具有较大的代表性基本体积（REV）大小，并且遵循指数规律。