OPS/ SiroModel

Provider: CSIRO


Development of the OPS/SiroModel, as part of the original Large Open Pit Mine Slope Stability Project (LOP I), allows the user to create a model of a section of an open pit excavation for slope stability analyses. It also includes a multi-function discrete fracture network (DFN) generator. This allows deterministic discontinuities such as bedding planes and faults and deterministic joints to be added to this model. Stochastically generated joints can also be generated upon each simulation by defining the statistical parameters for each set. Precedence settings can be used to control the way various discontinuity sets terminate against each other. The software will determine the intersections of all these structures and the presence of all complete blocks within the model, known as a block model (also known as a polyhedral model). Statistics on each block can be generated, including limit equilibrium stability assessment, and the blocks can be viewed individually or as an ensemble. A batch of simulations can be run constituting a Monte Carlo analysis which can then be analysed.

SiroModel uses polyhedral modelling techniques to create a 3D structural model of any section of the pit and perform analyses such as limit equilibrium, excavation plane interrogation and break-back estimation at both single bench and inter-ramp scale.  The software allows the user to either specify joint set parameters for the creation of a DFN or import a pre-determined DFN.  A user-defined pit geometry can be used or, alternatively, either a Sirovision 3D image or a DXF format surface file can be imported.  The software will allow the user to ‘simulate’ the mining of the pit to see if the changes in the pit geometry will have any effect on the stability of the benches and structurally controlled inter-ramp slopes.  In the analyses all possible block and wedge combinations are evaluated to produce estimated cumulative frequency curves for the effective face angle and the amount of break-back for that bench.  At the inter-ramp scale the analysis looks for potentially unstable block and wedge combinations (polyhedra) across all of the benches that are stacked on the inter-ramp geometry that is being assessed.

For more information about the software, see here. OPS/SiroModel Software Manual is also available here .