Predictive modelling of structure evolution in sandbox experiments

Abstract

In this paper a computational approach is presented that is able to forward model complex structural evolution with multiple intersecting faults that exhibit large relative movement. The approach adopts the Lagrangian method, complemented by robust and efficient automated adaptive meshing techniques, a constitutive model based on critical state concepts and global energy dissipation regularized by inclusion of fracture energy in the equations governing state variable evolution. The efficacy of the approach is benchmarked by forward simulation of two extensional analogue experiments that exhibit the development of a roll-over anticline with a series of superimposed crestal collapse graben systems. These sandbox experiments are excellent benchmarks for computational models, as both intersecting localisations with different rates of slip and large relative movement on localisations must be represented, while other complex phenomena associated with structural evolution over geological timeframes are not present.