As well as flow through joints, 3DEC 5.2 is capable of simulating fluid flow through the blocks or the matrix (i.e., between the joints). It is assumed that the blocks represent a saturated, permeable solid, such as soil or fractured rock mass. The flow in the matrix is coupled to the flow in the joints such that fluid in the joints can flow into the surrounding matrix (i.e., leak-off). As with the joint flow, the matrix flow modeling may be done independently of the usual 3DEC mechanical calculations or, in order to capture the effects of fluid/solid interaction, it may be done in conjunction (i.e., coupled) with the mechanical modeling.
Several characteristics are provided with the fluid-flow capability.
- Different zones may be assigned a different (isotropic) permeability.
- Fluid pressure flux and impermeable boundary conditions may be prescribed.
- Fluid sources (e.g., wells) may be applied as either point sources or line sources. These sources correspond to either a prescribed inflow or outflow of fluid, and may vary with time.
- Any of the mechanical and thermal models may be used with the fluid-flow models. In coupled problems, the compressibility and thermal expansion of the saturated material are accounted for.