DFNSC: A particle tracking discrete fracture network simulator considering successive spatial correlation

Abstract

Discrete fracture network (DFN) models are currently a suitable tool representing the anisotropic and discontinuity features of fractured media. Literatures has shown that it is challenging to obtain accurate DFN considering the quantitative spatial correlation in DFN modeling. This study proposes a particle tracking simulator for DFN modeling considering the successive spatial correlation of fracture distribution (DFNSC) by coupling fracture generating method, groundwater flow and solute transport theory, graph theory, and random walk method. By carrying out simulation calculations of seepage field and particle tracking on four DFNs with different distributions, more detailed conclusions have been obtained: The areas with dense fracture distribution have smaller hydraulic gradient than areas with sparse fracture distribution. The high flow velocity basically appears in the areas where the fractures are relatively sparse. Dense areas of fractures hinder the migration of particles. In essence, dense fractures create a low velocity zone, which makes the transport speed of solute particles slower. In the DFN with uniformly distribution and centralized distribution of fractures, the proportion of penetrating particles reaches 100%, whereas it is only 62% in the DFN with fractures gathered on one side. This study can provide reliable technology for the calculation of the seepage field of fractured media and the study of the pollutant migration process.