Fractures can be generated stochastically or discretly with SPRING. Any number of lithologic layers with individually different fracture orientations can be combined. The generated FE-meshes can be modified and parameterized with specific modules. The characteristic flow and transport processes are fully integrated into the calculation model.

Fractures are due to the greater flow rates dominant ways for the mass transfer in hard rock. Based on the high concentrations in the fracture, the accompanying materials are distributed in the surrounding rock matrix.

Normal to the fracture the concentration decreases rapidly. In order to approximate the material distribution optimally rows of nodes are generated in logarithmic intervals parallel to the fracture.

The left figure shows the cross-linking of two intersecting fractures. Normal to the fracture direction slender elements are generated. At the intersection of the fractures a flow channel can arise.

The right figure shows the visulization of fractures in SPRING.

The simulation of flow and transport in fractured sandstone clearly shows the characteristic processes. The flow velocity in the fractures is much greater than in the rock material. The direction of the fractures determines the potential distribution. Dominant flow paths arise by connected fractures. Entrained materials are transported through the fractures in the sandstone.