Modeling

Pillar yielding in retreat room-and-pillar mine (LAMODEL)

Numerical modeling techniques are a powerful mine design tool, and can be used as a practical means of evaluating or comparing mining alternatives before costly experimental mining.  AAI has the expertise and capabilities to perform stability analysis and simulation of underground mine structures, surface excavations, or solution mining caverns at any point in a mine’s life cycle.  Geologic structure, differing rock properties, rock strengths, time-dependent behavior, excavation geometries, linear and non-linear materials, backfill, and ground support elements can be incorporated into the numerical modeling analysis. 

Numerical methods employed include finite element, boundary element (displacement discontinuity or fictitious force methods), finite difference, discrete element, and other special purpose codes.  For tabular mine layouts, the displacement-discontinuity methods have found wide application in both the two-dimensional (2D) and three-dimensional (3D) forms.  Special purpose codes are available to model shaft liner stresses and heat loads, either from emplaced heat sources, such as radioactive waste, or from ventilation cooling.

Tunnel sequencing with ground support elements and faults zones (FLAC3D)

Modeling experience includes:

  • Room-and-pillar stability
  • Longwall stability
  • Yield pillar behavior
  • Longwall shield loading
  • Floor heave
  • Block caving
  • Rock reinforcement
  • Subsidence
  • Solution cavern stability
  • Slope stability
  • Nuclear waste emplacement
  • Creep closure
  • Fluid flow in joints
  • Multi-seam mining
  • Thermal loading
  • Backfill support
  • Cavern and well heat loss

Modeling codes routinely used by AAI include:

CodeNumerical MethodCapabilities
FLACFinite difference2D static, dynamic, creep, fluid flow, and thermal (conductivity) analysis with full spectrum constitutive models for soil and rock
FLAC3DFinite difference3D version of FLAC for 3D geometries
UDECDistinct element2D analysis of blocky ground and large deformations
PFC3DBall code3D rock fracturing, caving, and material flow
EXPAREABoundary element2D elasto-plastic analysis of stress and displacement normal to mined seam
LAMODELBoundary element2D elasto-plastic analysis of stress and displacement normal to mined seam with lamination discontinuities
Phase2Finite element2D elasto-plastic finite element stress analysis program for underground or surface excavations in rock or soil
SDPSInfluence/profile function2D and 3D surface subsidence prediction for underground mining
FLAC/SlopeFinite differenceAdvanced factor-of-safety determination for rock and soil slopes in 2D
SEEP/WFinite element2D groundwater seepage and excess pore-water pressure dissipation analysis in soil and rock
KUBRIXMesh generatorAutomatic all-hexahedral mesh generation software for creating complex 3D model meshes

Closure at shotcreted intersection (FLAC3D)

Surface subsidence from block caving (PFC3D)