The only way to simulate significant tunnel
deformation, or ‘squeezing ground’ is to
properly capture the physics of highly deformed rock—if the extent and magnitude
of the damage in the model is wrong, the
displacements will also be wrong.

The realistic simulation of such extreme
displacements demands the highest standards
in mine simulation. A nocompromises
approach is needed for this
class of problem.

BAE uses Abaqus with our own in‐house
constitutive models for jointed, anisotropic
rock and structure to enable the
simulation of extreme rock behaviour.

With BAEs constitutive models and higher
order, multi‐scale approaches, almost any
damage and dilation mechanism in rock
can be replicated.

The key to all our modelling is simple, sound modelling practice:

• Only higher order elements can be used. Lower order elements can’t be justified any longer
• Very small excavation steps are needed to capture the stress path.
• 2d modelling is now the exception, and 3d the rule
• Anisotropic, strain softening, dilatant constitutive models for rock masses and structure with an absolute minimum of assumptions about material behaviour to minimise error
• Multi-scale analysis. All BAE analysis starts with the assumption that phenomena at different length scales are coupled.
• Rigorous calibration, and homogenisation of material properties

The combination of these principles leads to more reliable forecasting and more resilient designs, and BAEs research working in extreme mining over many years has shown they are necessary to achieve sufficient results.