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In addition to our popular commercial software, Itasca also develops innovative, cutting-edge software for research and consulting purposes. Companies, agencies, or organizations that sponsor this work have access to use software that is well ahead of curve and influence further development. Although such software is not available for sale to the public at large, Itasca engineers and scientists may utilize this software for your engineering design and analysis needs.
Currently, Itasca is actively developing the following consulting software.
Since 2001, Itasca has been a member of the Hybrid Stress Blast Model (HSBM) project with the goal of developing a numerical model of the rock blasting process. The software created by Itasca, called Blo-Up, uses a unique combination of continuous and discontinuous numerical methods to represent the key processes occurring during blasting.
Blo-Up is a three-component coupled model of rock blasting. A coupled modeling approach was chosen because no single numerical technique was found to adequately describe all the physical phenomena occurring during blasting. The three components are (i) a continuum geomechanics model for the early-time detonation and near-field crushing; (ii) a brittle discrete element model for stress wave propagation, fracturing and burden movement; and (iii) a gas product model for burden acceleration by gas expansion, fracture flow, and atmospheric venting.
Itasca utilizes REBOP (Rapid Emulator Based On PFC) to simulate material drawdown within a block, panel, or sublevel cave mine by tracking the growth of draw zones (also called Isolated Movement Zones, IMZs) and corresponding fragmented rock flow associated with each drawpoint. The incremental laws governing IMZ growth and material movement in REBOP were derived on the basis of flow patterns observed in PFC3D and FLAC simulations of draw conducted by Lorig and Cundall (2000) and Pierce (2010) and in physical models conducted by a number of different researchers.
The key inputs to REBOP include fragment size distribution, initial and bulked porosity, friction angle and intact strength. The primary output from a draw analysis includes time- or tonnage-based histories of extracted ore grades and other rock properties, plots of material distribution above the drawpoints, and three-dimensional visualization of the movement and extraction zones associated with each drawpoint.
Secondary fragmentation, rilling, fines migration, and drawpoint hangups can be accounted for within REBOP simulations. The rilling logic and the ability to represent complex surface topography allow simulation of the impacts of local or large-scale failures in overlying open pit slopes or weak overburden. In addition to estimating recovery and dilution, the fragmentation exiting drawpoints can be tracked to predict hangup potential and associated drawpoint availability. In sublevel caves, the percentage of ring ore reporting to different sublevels can be tracked (i.e., primary, secondary, tertiary recovery) and tracer markers can be used to test the code against the results of in-situ marker trials.
Conventional numerical methods of slope analysis are mainly based on continuum approximation of the rock mass and the assumption of shear failure. Slope Model utilizes a novel approach that performs simulations of selected 3D sectors of rock slope stability in hard, fractured rock masses, consisting of any number of planar benches. The software implements a version of the Synthetic Rock Mass (SRM) approach (Pierce et al., 2007) applied to the specific case of rock slopes. SRM allows movement on joints (sliding and opening) as well as fracture of intact rock. The rock mass contains joint segments derived from a user-specified DFN (discrete fracture network). Non-steady fluid flow and pressure within the network of joint segments are modeled, and several aspects of fluid-rock interaction are represented, such as effective stress (for sliding behavior) and pressure response due to changes in rock geometry (e.g., bench removal). This three-dimensional modeling software is based on a lattice scheme that handles discontinuities and new fractures in the same way as Distinct Element Method (DEM), but is five to ten times faster. Fluid flows in the joints and rock matrix, and the flow network is automatically extended as new fractures form. Slope Model was developed as part of the Large Open Pit (LOP) Project.
The left-hand photograph is from Adhikary et al (1997), corresponding to his centrifuge Test 7, showing post-failure deformation of a toppling assembly of layers oriented with initial dips of 69o, and a slope angle of 70o. The right-hand plot is from a lattice simulation of a similar system, after failure (but limited to small strain deformation). The black dots denote broken bonds, and the colored vectors denote displacements (where red is large displacement and blue is small displacement). The red fracture line, derived from the centrifuge result, is superimposed upon the numerical result.
Slope failure through fracture of intact rock bridges modeled with Slope Model; black dots indicate stress-induced cracks (Lorig et al., 2010).
XSite is a novel hydraulic fracturing numerical simulation program based on the Synthetic Rock Mass (SRM) approach and the Lattice method. The software is capable of modeling hydraulic fracturing from multiple wellbores with multiple stages and clusters, including open-hole completions and perforation tunnels. Fracture interaction — including propagation in naturally fractured reservoirs, approximated using discrete fracture networks (DFNs) — is automatically handled. Synthetic micro-seismicity can be tracked and recorded. The model executes fully coupled mechanical and fluid flow simulations. The fluid flow is simulated within the fracture network and rock matrix. Proppant transport and placement logic may be activated. All results, including stimulated permeability and porosity fields, may be exported to reservoir simulation software.
Advantages of XSite include:
- No assumption regarding the fracture shape of trajectory
- Interaction between multiple hydraulic fractures and hydraulic fractures and joints
- Fracture propagation in inhomogeneous and fractured rock masses