Izak Gerhardus Morkel

• Consultant at IGM Geotechnical

The hazard posed from large seismic events is often high enough to warrant the exclusion or evacuation of personnel from underground workings. A period of exclusion is often determined following blasts or large events due to the increased risk. The period of exclusion until re-entry occurs is a decision for site geotechnical engineers and mine mana...

Reliable assessment of seismic hazard plays a vital role in addressing geotechnical risk in many mines. The data quality and assessed risk can be adversely affected by bandwidth limitations of the sensors in the mine’s seismic network. The influence of sensor bandwidth on the recorded waveforms is well understood and has been observed from as early...

It is generally accepted that the ratio of energy associated with the S-wave (Es) and P-wave (Ep) is dependent on the focal mechanism (Mendecki 2013). In the mining industry, the ratio of S-wave energy to P-wave energy is regarded as an important indicator of the type of focal mechanism, with the ratio being lower for explosive sources and higher f...

The occurrence of seismicity in high stress underground environments is common and often leads to underground damage, affecting both the safety and profitability of a mine. To manage this risk, it is typical for a mine to install a seismic sensor array which is used to assess the seismic conditions around the excavations and monitor any changes to...

As mines around the world get deeper and the stresses around the excavations increase, the occurrence of large damaging seismic events (often called rockbursts) become more commonplace. One of the most favoured controls used in the industry to reduce damage from large seismic events is the implementation of a ground support system. Such a system ty...

Accurate assessment of seismic source mechanisms is important in seismic monitoring in underground mines. Complexities in seismic source identification, particularly inconsistencies in datasets, may significantly impact the interpretation and accuracy of seismic data analysis. To address this issue, a method for identifying seismic source mechanism...

The full text is available here: https://papers.acg.uwa.edu.au/d/1952_10_Potvin/10_Potvin.pdf The management of seismic risks in metalliferous mines operating in developed mining countries such as Australia, Canada, Chile and Sweden has been very successful during the last decade. The occurrence and magnitude of large seismic events in deep mines...

The occurrence of seismicity in high stress hard rock mines poses a challenge to geotechnical engineers and mine management around the world. Only a few practical options are available when the mitigation of seismic risk is considered. One of the most widely used options is the implementation of a re-entry protocol. These protocols are useful at li...

Due to the complex nature of the seismic response to mining, geotechnical engineers often require back analysis to provide a base line against which to interpret future behaviour. This practice assumes, and is reliant on, the database being consistent in space and time. Few tools are available for geotechnical engineers dedicated to the task of qua...

Over the years there have been several attempts to undertake routine real-time microseismic monitoring of open pit mine slopes. This technique has been commonly used in underground operations to manage induced seismicity and rockburst. However, the microseismic monitoring in open pits is still experimental and further studies are required. In this...

Thesis (M.Sc. (Physics))--North-West University, Potchefstroom Campus, 2008.