Numerical modelling of time-dependent deformation around an underground mine in rock salt

Extensive in-situ and laboratory-based experimental work formed the basis for an assessment of the stability of an abandoned panel of Winsford salt mine, Cheshire, England, conducted by numerical modelling with the finite-difference code FLAC. The final model is composed of a Burger rheological component to represent the time-dependent deformation of the salt sequences and a Mohr-Coulomb constitutive model to simulate the behaviour of the non-creeping marl strata. The results of the creep model are compared with actual convergence monitoring data for validation purposes. The results indicate that the section of the mine is stable and confirm the presence of an inherently stable core in each of the internal pillars within the panel