25th Mine Seismology Seminar

Transcription

1 25th Mine Seismology Seminar Seminar: April 2015, Asara Wine Estate, Stellenbosch Sunday 19 April 09h00-16h30: Meeting of the International Research Advisory Board of the Institute of Mine Seismology Sunday 18h00 - Ice-Breaker hosted by the Institute of Mine Seismology Monday 20 April 08h45: Lectures and Presentations on Passive and Active Microseismic Monitoring in Mines Monday 18h30: Dinner in the Vineyards hosted by the Institute of Mine Seismology Tuesday 21 April 09h00: Lectures and Presentations on Modelling & Monitoring the Seismic Rock Mass Response to Mining Training Courses: April 2015, Asara, Stellenbosch 19 April, 09h00-16h00: Seismology Primer 22 April, 09h00-13h00: Deformation Based Support Design, Prof. Peter Kaiser 22 April, 14h00-18h00: Short, Intermediate and Long Term Seismic Hazard in Mines 23 April, 09h00-13h00: Monitoring & Analysis of Seismicity: Ticker3D & Vantage 23 April, 14h00-18h00: Integration of Stress Modelling and Seismic Data in Vantage 24 April, 09h00-13h00: Seismological Processing of Waveforms with Trace For more information on registration, accommodation and social programme please contact Rynelle.Eksteen@IMSeismology.org.

2 Objectives of the 2015 Seminar Considerable progress has been made in the quantification of seismic sources and in the quantification of seismicity. Most modern seismic systems quantify seismic sources by their seismic potency, moment and their tensors, radiated seismic energy and other derivatives. Seismicity is routinely characterised by its size and time distributions, including spatial and temporal clustering and migration, and by parameters reflecting changes in the strain and stress regime and the rheological properties of the rock mass deformation associated with the seismic radiation. Although seismic waveforms do not provide direct information about the absolute stresses and strains, they do provide useful information about stress orientation and about the spatial and temporal strain and stress changes. There is recent progress in integration of seismic observations and numerical stress modelling. Most applications to date were limited to qualitative correlation between location and mechanisms of events with the modelled stresses. We will report encouraging results on the quantitative correlation that makes it possible to improve numerical modelling. Over the last few years we ve made a considerable progress in the quantification of rock mass properties and monitoring their changes in space and time. Recent advances in active seismic monitoring, seismic interferometry and ambient noise analysis achieve a resolution at least 100 times better than classical seismic velocity inversion. This may be of great help in delineating geological structures and in reducing the uncertainties in stress modelling. We will also discuss methodologies to assess long, intermediate and short term seismic hazard for mines using seismic catalogues. It will include data selection, issue of the maximum magnitude event, the power law size distribution and its intricacies, recurrence times and re-entry probabilities. We will also discuss uncertainties and limitations of the method. The seismic hazard lecture and the training course is based on the Mine Seismology Reference Book: Seismic Hazard by A. J. Mendecki, Institute of Mine Seismology, to be published in June The main objective of the 2015 Seminar is to present recent progress made in passive and active seismic monitoring and in integration of numerical modelling with seismic data. The main themes of the Seminar are: - Progress in Passive Seismic Monitoring - Integration of Numerical Modelling with Seismic Observations - In-Mine Seismic: In-mine Exploration and Rock Mass Characterisation - Methodologies to Estimate Induced Hazard - Case Studies I m asking all presenters to tell us: (1) why you did this work, (2) how you did it, (3) what you found, (4) what you think it means, and (5) what are the limitations. Looking forward to see you in Stellenbosch, South Africa in April 2015 Aleksander J. Mendecki Chairman and Head of Research Institute of Mine Seismology

3 25th Mine Seismology Seminar Day 1 Monday 20 April, Asara Wine Estate, Stellenbosch 08h30 Welcome and Introduction Dr Aleksander Mendecki, Chairman, Institute of Mine Seismology 09h00 Overcoming Challenges of Rock Mass Characterization for Underground Construction in Deep Mines Prof. Peter Kaiser, CEMI, Canada 09h30 Dynamic Rock Related Hazards in Mines Dr David Beck, Beck Engineering, Australia 10h00 Dynamical Modelling of Source Rupture: Theoretical Formulation and Numerical Modeling Dr Vladimir Lyakhovsky, Geological Survey of Israel, Jerusalem 10h30 Dynamical Modelling of Source Rupture: Numerical Results Dr Assen Ilchev, Institute of Mine Seismology - Tea Break - 11h30 Simulation of Flow Branching and Associated Deformation Mechanisms in Fluid Driven Fracture Propagation Dr John Napier, Univerity of Pretoria, South Africa 12h00 Characterizing Underground Openings Using Seismic Resonances Dr Andrew King, CSIRO, Australia 12h30 In-Mine Reflection Seismics Using Microseismic Event Sources Dr Richard Lynch and Gerrit Olivier, Institute of Mine Seismology - Lunch - 14h00 Overview of the Japanese-South African Collaboration in Mine Seismology Research Since 1992 Prof. Hiroshi Ogasawara, Ritsumeikan University, Japan 14h30 Micromechanics of Quartzite Prof. Ray Durrheim, University of the Witwatersrand, South Africa 15h00 Spatial and Temporal Mapping of Ground Motion for Mines Dr Ernest Lötter, Institute of Mine Seismology - Tea Break - 16h00 Quantification of Discrepancy Between Numerical Stress Models and Seismic Data Dr Dmitriy Malovichko & Gys Basson, Institute of Mine Seismology 16h30 Active and Ambient Noise Seismic Monitoring - Latest Results Gerrit Olivier, Mark Green Dr Richard Lynch, Institute of Mine Seismology 17h00 Mine Seismology Reference Book: Seismic Hazard Dr Aleksander Mendecki, Institute of Mine Seismology 18h30 Dinner in the Vineyards hosted by the Institute of Mine Seismology

4 25th Mine Seismology Seminar Day 2 Tuesday 21 April, Asara Wine Estate, Stellenbosch 09h00 A Rock Mechanical Analysis of Seismic and Geological Data for Two Large Damaging Events in the Kiruna Mine Christina Dahnér and Ulf Andersson, LKAB, Sweden 09h30 Seismological Analysis of Two Large Events in the Kiruna Mine Dr Dmitriy Malovichko, Ernest Lötter and Stephen Meyer, Institute of Mine Seismology 10h00 Numerical Modelling of Seismic Potency in Tabular Mines and Applying it for Mine Layout Design. Gerhard Hofmann, AngloGold Ashanti, South Africa 10h30 Microseismic Activity Monitoring and Rockburst Warning in Jinping II Hydropower Station, China Dr Bing Rui Chen, Institute of Rock and Soil Mechanics, Academy of Sciences, China - Tea Break - 11h30 Rock Failure and Pillar Stability in the Rustenburg Platinum Mines Dr Gerrie van Aswegen, Institute of Mine Seismology 12h00 A Method to Assess Pillar Stability in the Rustenburg Platinum Mines Richard Clark, Jacques Gerber and Gerrie van Aswegen, Institute of Mine Seismology 12h30 Micro-seismic Monitoring Stability of Pre-underground Mined Cavities in Supporting Existing Open Pit Mining Dr Yu Sheng, Beijing SCR Instruments, China - Lunch - 14h00 Material Properties, Failure Mechanisms and Source Parameters Shana Ebrahim-Trollope, University of Cape Town 14h30 Examples of Kinematic Modelling of Ground Motion in Mines: Nonhomogeneous Rock Mass and Free Surface Effects Wichard Sullward, Dr Daryl Rebuli, Institute of Mine Seismology 15h00 Seismic Hazard Rating for Mines: Polygon and Polygonless Approach Dr Daryl Rebuli, Shane Kohler, Cornel du Toit and Wichard Sullward, Institute of Mine Seismology 15h30 Brightness Location of Events with Complex Waveforms Tjaart de Wit, Dr Dmitriy Malovichko and Stephen Meyer Institute of Mine Seismology 16h00 Multinomial Classification of Events to Reduce Pollution of Seismic Dataset by Blasts and Ore-pass Noise Dr Dmitriy Malovichko & Stephen Meyer, Institute of Mine Seismology

5 Pre-Seminar Course: Seismology Primer Sunday 19 April, 09h00-16h00, Asara Wine Estate, Stellenbosch Instructors: Dr Daryl Rebuli & Olaf Goldbach, Institute of Mine Seismology. Course Objectives. The objective of the course is to explain basic seismological concepts of seismic waves and sources to non-seismologists to facilitate better understanding of lectures, presentations and training courses offered during the Seminar. Course Programme. 1. Safety objectives of seismic monitoring: rescue, prevention, hazard assessment, alerts and back analysis. 2. What is a seismic event, types of seismic waves, sources of seismic waves, acceleration, velocity and displacement of ground motion (particle velocity) vs. wave speed (propagation velocity). 3. Event locations and location errors, design principles of seismic network configuration, velocity calibration, calibration blasts and Wadati diagram. 4. Direct source parameters: origin time and location, Fourier transformation, frequency decomposition, spectra and spectral parameters, seismic potency, seismic moment, radiated energy, corner frequency and size. 5. Derived source parameters: static and dynamic stress drop, apparent stress, apparent volume, energy index. 6. Magnitude scales: local magnitudes, moment or potency magnitudes, energy magnitudes. 7. Types of faults, radiation patterns and fault plane solutions, stress orientation. 8. Size distribution (Gutenberg-Richter relation), seismic hazard and risk, probabilities and hazard maps. 9. Clustering, time histories of seismic parameters, histograms, cumulative plots. Presentation and the relevant publications will be available in electronic format. Post-Seminar Courses Deformation Based Support Design for Static and Dynamic Conditions Wednesday 22 April, 09h00-13h00, Asara Wine Estate, Stellenbosch Course Instructor: Prof. Peter K Kaiser. Peter is Professor and Chair for Rock Mechanics and Ground control at the Bharti School of Engineering, Laurentian University, Sudbury, Canada. He is the former Founding Director of the Centre for Excellence in Mining Innovation and the former Director of the Rio Tinto Centre for Underground Construction. He is a specialist in applied research for mining and underground construction with expertise is in geomechanics, tunneling, and applications of new technologies to mining operations in order to increase safety and productivity. He is a specialist in applied research for u/g mining and construction and brings extensive experience from both the industrial and academic sectors having served as consultant to numerous consulting engineers, mines, and public agencies. He has supported contractors and mining companies in claims and litigations. Dr. Kaiser is the author of more than 300 technical and scientific geomechanics publications. He is a Fellow of the Engineering Institute of Canada and the Canadian Academy of Engineers.

6 Brief Description Hard rock mines are progressing to great depths and hard rock tunnels are being conducted in some countries at depth exceeding 2000 m. Mining companies are planning to develop super-caves, some for depths approaching 2000 m. As mining and civil tunnelling progresses to deep grounds, mining-induced stresses cause rock mass failure of hard rock with static and dynamic impact on ground support. Both can lead to large bulking deformations that are imposed in a static or dynamic manner on the rock support. During this workshop, brittle rock mass failure processes will be reviewed within a frame work of support selection for highly stressed ground. Deficiencies in current approaches will be discussed with the intent of pointing the way to more rational support design methods for conditions experiencing mining-induced stress change. Clearly, excavation-induced seismicity and rockburst problems increase with depth and cannot be prevented. Whereas the seismic risk can be reduced by selecting appropriate mining methods and sequences and by strategically placing developments and infrastructure, the last line of defence always comes from effective static and burst-resistant rock support systems that prevent or minimize damage to excavations and thus enhance workplace safety. This half-day workshop is intended to stimulate discussion on the above described engineering challenges. The presentations will cover limitations of standard support design by classification, aspects of deformation-based support design, limitations of groundmotion-based burst-support design, engineering challenges of strain-bursting ground, methods to control and mitigate seismic risk by use of support to mitigate damage. The workshop content will largely cover in more detail material presented in keynote lectures presented by the author in 2013 and at conferences such as Support 13 in Australia and RASIM8 in Russia. The dynamic aspects are based on research findings from the Canadian Rockburst Support Handbook (CRBSHB, Kaiser et al. 1996) supplemented with recent developments and experiences as well as a design tool, called Burst- Support, which significantly simplifies the support design task for burst prone ground. Through a mix of lectures, demonstrations, and active discussions with the attendees, the science, the art and practical aspects of support selection will be explored. Some reference material will be distributed to the registrants in electronic format. Assessing the Long, Intermediate and Short Term Seismic Hazard for Mines Wednesday 22 April, 14h00-18h00, Asara Wine Estate, Stellenbosch Course Instructor: Dr Aleksander Mendecki, Institute of Mine Seismology 1. Long, intermediate and short term hazard Definitions and objectives 1.1 Formal definition of seismic hazard. 1.2 Seismic hazard and seismic hazard potential. 2. Maximum event size 2.1 Maximum possible even size in a mine Balance of the effective volume mined and maximum event size Size of a mine and the maximum event size Influence of local tectonic and regional mining. 2.2 The size of the next largest event. 3. Intermediate term hazard 3.1 Size distribution of seismic events in time and in volume mined domain. 3.2 Parameter estimation of the size distribution and associated errors. 3.3 Stationary Poisson process. 3.4 Size distribution and stationary Poisson process Probabilities. 3.5 Probabilities of exceedance vs event size for different time intervals. 4. Long term hazard

7 4.1 Recurrence times and associated event sizes for long term hazard. 4.2 Probabilities of exceedance vs time for event sizes with long term recurrence. 5. Short term hazard 5.1 Step loading and relaxation process. 5.2 Relaxation functions. 5.3 Non-homogeneous Poisson process. 5.4 Size distribution and non-homogeneous Poisson process Probabilities. 5.5 Short term hazard time interval probabilities of exceedance. 5.6 Re-entry probabilities. 6. Uncertainty 6.1 Types of uncertainty. 6.2 Interpretation and bias. The course is based on Mine Seismology Reference Book: Seismic Hazard by A. J. Mendecki, Institute of Mine Seismology, to be published in June Presentation will be made available in electronic format. Monitoring Seismicity & System Performance with Ticker3D and Seismic Visualisation and Analysis with Vantage Thursday 23 April, 09h00-13h00, Asara Wine Estate, Stellenbosch Course Instructors: Dr Dmitriy Malovichko, Dr Ernest Lötter, Dr Daryl Rebuli & Gys Basson, Institute of Mine Seismology 1. Ticker3D (14h00-15h30) 1.1 Initial Configuration. 1.2 System Health and Management Viewing health of system components Sensitivity Analysis. 1.3 Recent seismicity. 1.4 Long term seismicity Event Filters Time History, Size Distribution and other plots Spatial contours of seismicity Spatial clustering. 1.5 Production Data Management. 1.6 Basic Reports. 2. Vantage Visualisation 2.1 Interacting with the 3D viewer. 2.2 Loading and customising mine plans. 2.3 Loading seismic data from IMS Database Server. 2.4 Colouring and sizing of events. 2.5 Parameter, temporal and spatial filtering of the data. 2.6 Displaying source mechanisms. 3. Vantage Analysis 3.1 Analysis in temporal, spatial and parameter domains Time histories Contours (event parameter gridding onto meshes) Energy-potency or energy-moment plots Rank statistics of ground motions. 3.2 Event size distribution: open-ended and upper-truncated models, maximum size of event, probability table

8 3.3 Source mechanisms: stereo-net of principals axes, nodal planes and poles, Hudson s source type plot, Frohlich s ternary graph. Attendees with modern laptops will receive a license for Vantage with which to perform hands-on tasks during training and gain experience. Presentation used during the course and the relevant publications will be available in PDF format. Note that in order to run Vantage, we strongly recommend a machine with at least 4GB of RAM and a modern 3D graphics card (NVidia or AMD) with up to date drivers installed. Integration of Stress Modelling and Seismic Data in Vantage Thursday 23 April, 14h00-18h00, Asara Wine Estate, Stellenbosch Course Instructors: Dr Dmitriy Malovichko, Dr Gerrie van Aswegen, Jacques Gerber, Institute of Mine Seismology 1. Introduction to IMS boundary element code (ISSM) 1.1 Building the model of tabular and 3D orebodies 1.2 Solving the model 1.3 Calculation of principal stresses and modelling parameters 1.4 Visualisation of results: vectors, meshes and data points, charts 2. Using the 3rd party stress modelling data 2.1 Importing the stress data 2.2 Calculation and visualisation of principal stresses and modelling parameters 3. Some aspects of seismic data 3.1 Location of sources: uncertainty of location 3.2 Source mechanisms: orientation settings, automatic moment tensor inversion 4. Validation and improvement of numerical stress model using seismic data 4.1 Absolute and differential stresses vs location and source parameters of events: comparing in 3D, correlation plots 4.2 Stress orientation vs seismic source mechanisms: comparing in 3D and using stereonets, stress inversion 5. Modelling and assimilation of seismicity 5.1 Simulation of seismicity using Salamon-Linkov approach 5.2 Incorporation of seismicity into the boundary-element model Presentation and the relevant publications will be available in electronic format. Seismological Processing with IMS-Trace Friday 24 April, 09h00-13h00, Asara Wine Estate, Stellenbosch Course Instructors: Dr Ernest Lötter, Dr Daryl Rebuli, Institute of Mine Seismology 1. Location Primer 1.1 P- and S-wave arrival picks. 1.2 Polarisation analysis. 1.3 Locating seismic events: absolute, relative or with ray tracing. 1.4 Marking events as accepted, rejected or blasts. 1.5 Travel time processing. 2. Source Parameter Primer 2.1 Basic source parameters: seismic energy, seismic potency and moment, magnitude. 2.2 Derivative source parameters: apparent stress, energy index, apparent volume.

9 2.3 Source spectra. 2.4 How to improve source parameter estimates. 2.5 Mechanisms of seismic events Decomposition plots Hudson diagram. 2.6 Dealing with noisy data. 3. Velocity Structure 3.1 Velocity calibration. 3.2 Wadati diagrams. 3.3 How to build a 3D velocity model. 4. Alternative Ways to Browse Seismic Data 4.1 Exporting information from the database. 4.2 Parameter filters. 4.3 Automatic queries. 4.4 Exporting seismograms. 5. User Management 5.1 Plugin installation Viewing events in 3D. 5.3 Integration with IMS-Vantage. Attendees that will bring a modern laptop will receive a license for IMS-Trace with which to perform hands-on tasks during training and gain experience. Presentation used during the course and the relevant publications will be available in pdf format.