Itasca's office in Minneapolis recently has expanded to provide more office and conference room space. We now have three conference rooms and nearly 50 individual offices. In addition, our training facility has been substantially upgraded. We have several offices available for visitors and we encourage clients to visit and work directly with us on their projects. Such visits give clients a chance to see how we work and meet other Itasca staff. I hope you will consider visiting our expanded Minneapolis office or any of our other 15 offices around the world in the near future.
— Loren Lorig, Chief Executive Officer
Itasca has been working with AngloGold Ashanti in South Africa to understand rock behavior, especially brittle failure mechanisms, inherent in deep gold mines in South Africa. The ultimate goal of this work is to develop a rational methodology for mine design, especially as mining continues deeper. Itasca is doing this by developing a generic mechanical model for rock behavior around advancing stopes in deep gold mines that can reproduce the induced fracture patterns. The work will allow fracturing mechanisms to be explored, and then relate them to in-situ conditions such as parting planes, in-situ stresses and existing mining geometry. Two approaches have been employed to develop a modeling environment for stope-scale systems. The first approach is continuum-based and utilizes the Mohr-Coulomb strain softening model using FLAC alone. The second approach employs a coupled continuum-discontinuum technique, where the continuum region is modeled by FLAC and the discontinuum region is modeled by a PFC2D model embedded within a larger FLAC model.
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Both investigated approaches produce well-defined shear fractures and stope-parallel extension fractures similar to those observed in the field. In the coupled FLAC-PFC2D models, the bonded-particle material exhibits formation of conjugate shear fractures that correspond with shear fractures in the continuum material. Additional damage structures appear to be present within these shear fractures — e.g., en echelon fracturing in the bonded-particle material is similar to what is observed in actual shear fractures underground. There is also evidence of spalling at the stope face, distributed damage ahead of the stope face and formation of extension fractures. Therefore, the coupled model successfully exhibits a richness of localized detail in the simulated damage, while the surrounding FLAC grid provides for large-scale models to be implemented.
Brummer, R.K., and A.J. Rorke. (1984) “Mining Induced Fracturing Around Deep Gold Mine Stopes,” COMRO, unpublished research report 38/84, project GR3FO1, July.
Applied Seismology Consultants
Congratulations to Xueping Zhao and Jen Andrews (ASC) who received the award for Best Presentation and Quality Content in the EGS8 session at the Geothermal Resources Council Annual Meeting, for their paper "Optimized EGS Reservoir Stimulation Using Microseismic and Numerical Methods."
Itasca Houston, Inc.
Marisela Sánchez-Nagel, Itasca Houston GM, has been selected to serve as SPE Distinguished Lecturer for the 2012-2013 period. Each year SPE selects a group of individuals who are experts in their field and capable speakers to share their expertise with SPE members through visits to local sections around the world. The individuals are nominated by their peers, and selection by the Distinguished Lecturer Committee is a recognition of their expertise.
HydroChina Itasca R&D Center
The ISRM World Congress was held in Beijing where Matt Pierce and Charles Fairhurst presented a joint keynote talk, “Synthetic Rock Mass Applications in Mass Mining.” In addition, the official opening of the HydroChina Itasca R&D Center (HIC) was held in Hangzhou and was celebrated with a Colloquium entitled “Progress and Challenges in Rock Mechanics” on October 24, 2011. Around 120 people attended from around the world and included invited guests prominent in rock mechanics and engineering.
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Spring Training Spaces Available
Space is available now for training courses to be held this April and May at the Itasca offices in Minneapolis. As with all our general training courses, registration is available on a first-come, first-served basis. If you are interested in attending, we encourage you to sign up now. The courses and course dates are:
FLAC – Apr. 11-13, 2012
Details and registration information can be found on our web site at www.itascacg.com/software/training.php.
Itasca is seeking a Senior Engineer in its Minneapolis office. Itasca is a growing international engineering company. The successful candidate will be responsible mainly for directing numerical analysis project work done by others and would interact with both Itasca engineers and clients on a regular basis. The projects are world-class providing exceptional professional opportunities working with highly regarded staff in our US and International offices. Some travel may be involved. The candidate should have a strong background (approx. 5 to 10 years) in geomechanics modeling with Itasca codes in mining applications and a demonstrated capability to mentor staff and direct projects. All candidates must have a Ph.D. degree in a related discipline. Please send a cover letter and resume to email@example.com and include the reference number ICG12-01 in the e-mail subject line.
Ph.D./Post-Doc Opportunity — The Civil Engineering Department at the University of Illinois is looking for someone to work on both static and dynamic applications with FLAC. If you know of someone who may be interested, please contact Timothy D. Stark, Ph.D., P.E., D.GE, F.ASCE, Professor of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign at firstname.lastname@example.org or email@example.com.
Bahrani, N., B. Valley, P.K. Kaiser and M.E. Pierce. (2011) "Evaluation of PFC2D Grain-Based Model for Simulation of Confinement — Dependent Rock Strength Degradation and Failure Process In CD Proceedings," ARMA 45th U.S. Rock Mechanics / Geomechanics Symposium (San Francisco, June 2011). Paper No. ARMA 11-156. A. Iannacchione, G. Esterhuizen and A. Tutunca, eds. Alexandria, VA: ARMA.
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