Simulation of hydraulic fracturing in rock mass using a smeared crack model

•A non-linear fluid-solid coupling model to simulate hydraulic fracturing is proposed.•An evolutionary characteristic length method for 3D smeared crack model is introduced.•An interface coupling method for transition from coarser mesh to finer one is proposed.

In this paper, a 3D smeared crack model with an evolutionary characteristic length is developed for the analysis of hydraulic fracturing in rock mass. A non-linear fluid–solid coupling finite element model is established and method for smeared cracking finite element model is presented. The evolutionary characteristic length method focuses on continuous adaptation of the crack band width which is based on the incremental finite element solution and the idea of nonlocal continuum. An interface coupling method is proposed to achieve the transition from a coarser mesh to a finer one. The results of two numerical examples indicate the superiority of the present formulation over the standard smeared crack model.