Modeling of near-surface bowl-shaped fractures

This paper aims to quantify, through numerical simulations, the geometry of an axisymmetric sub-surface crack subject to a uniform pressure simulating fluid or gas pressure. Two algorithms based on the displacement discontinuity method are employed: one that relies on symmetry, as the fracture is discretized into ring elements, and another one in which the fracture surface is represented by flat, triangular elements. The fracture propagation is modeled by adding new elements to the existing fracture, with the inclination of a new element determined from the maximum tensile stress criterion. The numerical results are compared with available results of simulations of bowl-shaped fractures and laboratory experiments.