Short Courses
Structural Geology Guidelines for use in burst-prone underground mines
A technical overview in preparation for a planned Fall 2012 Short Course
April 12, 2012
08:30 – 12:00
Willet Green Miller Centre - Auditorium
933 Ramsey Lake Road, Sudbury, Ontario
Wayne Barnett
Need for integration of 3D structural, geomechanical, and fault behaviour models
As mines progress to greater depths, health and safety and mine economic challenges, related to high stress conditions, are becoming more frequent. According to Simser (2008) seismic events in mines are tending towards following the rule that: 30% of events are blast triggered; 30% have some precursory activity; and 30% come 'out-of-the-blue'. With the increasing depth of mines and a large portion of events coming 'out-of-the- blue', there is a need to refine current rock engineering approaches which currently are not capable of adequately assessing rock mass and fault behaviour.
These talks are driven by the need for data to be systematically collected, appropriately interpreted, and coupled/integrated into 3D lithology, structural geology, and rock mechanics models. Based on the combined experience of CEMI, SRK, Golder, Queen's University and MIRARCO, it has been identified that one of the primary limitations to dealing with burst-prone mining situations is having available an appropriate and properly interpreted structural geologic model for a particular mine. An appropriate model contains specific detail on fault geometry, relative timing and properties. Although faults can have simple geometries during the early stages of formation, they often become much more complex when reactivated and at later stages of growth and evolution. In such situations, they may exist as a network of anastomosing or crosscutting structures.
Structural mapping of faults should adequately describe their geometric and material characteristics, as well as their crosscutting relationships with other structures. Both brittle and ductile formed faults are discussed as both can behave violently. Faults should not be thought of as single planar continuous structures, but rather as an association of segments with distinct characteristics and geometry. The common characteristic of structures to have a scale invariant (or self-similar) pattern is an important tool for mapping and interpretation. As it will be shown in the following talk, these geometric and material property characteristics of specific segments of a larger fault, control local rockmass behaviour.
Trevor Carter
Implications of Stress-Structure Interactions and Fault Behaviour on Mine Design and Planning for both Shallow & Deep Mining
On the basis that understanding the potential for initiating damaging seismicity and for inducing slip on pre- existing faults requires that mines gain a better understanding not only of their stope scale structure but also of their mine-wide structural environment, a Structural Geology Guidelines Manual has recently been prepared by Golder under contract to CEMI. This Manual has been targeted at assisting industry to improve current methods of rock mass and fault characterization at a mine wide scale, not just at drift scale. It is aimed at highlighting the importance of an improved geomechanics understanding during Mine Design, starting at the exploration stage and continuing through to the production. The reason for developing the Manual at this time has been the fact that many Mines are planning to go deeper and open bigger stopes, thereby increasing their risk of encountering, not just excavation induced seismicity, but also fault slip movements and even rockburst events.
This talk will outline a few of the tools and techniques from the Manual that can be helpful for improving current methods and approaches for geomechanical design of mine layouts. There will be some discussion of the inherent risks to not understanding structure on a mine-wide scale. The talk explores some of the pitfalls of using various types of geomechanical modelling and rock mass characterization approaches where the true influence of structure is all too often overlooked, even in what might be considered simple shallower mining situations.
The talk will also briefly touch on some of the methods and techniques for slip-tendency evaluation along structures, providing some case examples which assess the implications of mining induced stress change. This is critical to achieving mine designs which minimize the risks associated with geological structure complexity.
REGISTER NOW!
Deadline to register is April 6th, 2012. RSVP Jennifer Thomas at jthomas@miningexcellence.ca or Fax to 705.671.3878 ATTN: Jennifer Thomas
For further details, please contact Jennifer Thomas jthomas@miningexcellence.ca or call 705.673.6568 x 0
Parking will be available in the Visitor's lot (limited) of the Willet Green Miller Centre (free). Additional parking will be available in the Fraser parking lot across from the Willet Green Miller Centre (paid).