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

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