2D and 3D numerical analysis of fluid pressure induced fracture

Simulation of 2D and 3D hydraulic fracturing in fully-saturated, porous media is presented. The discrete fracture/s is/are driven by the fluid pressure. A cohesive fracture model is adopted where, in the 3D case, the fracture follows the face of the element around the fracture tip which is closest to the normal direction of the maximum principal stress at the tip. While in the 2D setting, the fracture follows directly the direction normal to the maximum principal stress. No predetermined fracture path is needed. This requires continuous updating of the mesh around the crack tip to take into account the evolving geometry. The updating of the mesh is obtained by means of an efficient mesh generator based on Delaunay tessellation. The governing equations are written in the framework of porous media mechanics and are solved numerically in a fully coupled manner. Numerical examples dealing with well injection in a geological setting and hydraulic fracture in a concrete dam conclude the paper. © 2013 American Society of Civil Engineers.