Stuart graduated from the University of Tasmania in 2011 with a Bachelor of Geotechnical Engineering. He has worked as a geotechnical engineer in Kalgoorlie for nearly five years, mostly focusing on managing seismic risk at Raleigh and Kanowna Belle. He completed a Master of Engineering Science (Mining Geomechanics) at Curtin University in 2016 where his thesis in the final semester was assisted by the ACG. Stuart joined the ACG as a research assistant for the mXrap Consortium in 2017 and started his PhD in 2018 looking to quantify the risk associated with short-term seismic exclusion zones.
View all authorsWith the holidays approaching we thought we would send everyone some mXmas presents! And obviously what everyone wants for mXmas are mXrap videos ?. These videos are not geotech related but come from various games, generative art, or physics simulations that we have made for fun.
Energy and moment are two independent measures of the strength of a seismic event. Their physical meaning and how they are calculated was described in a previous blog post. Analysis of the relationship between the energy and moment of events can provide insight into seismic sources. For example, blasts or ore pass noise, falsely processed as real events, tend to have distinct zones on an energy-moment chart. In general, events with higher-than-average energy are associated with high relative stress.
We have made a couple of changes to the Paste Backfill Design application since the original release. See the previous blog post for the main details of the app.
A few new features have been added to the Hazard Assessment application, aiming to improve usability, understanding and investigation. The first addition is a chart in the hazard setup window to indicate the current date range settings. Usually the date range for calculating b-value will be a lot longer than for calculating event rate. Hopefully the chart will be a handy visual aid to help you keep your bearings when setting the hazard analysis periods.
Two new charts have been added to the General Analysis application related to assessing hazard with the frequency-magnitude relationship.
Moment tensor analysis is a topic that carries a decent level of uncertainty and confusion for many people. So I'm going to lay it out as simply as I can. For this post, I'm not going to go into too many details on how moment tensors are actually calculated. But, I'm going to summarise the things I think are most important for geotechnical engineers to know for interpreting moment tensor results.
Moment tensors have been added to the General Analysis application in the recent update. Beach balls and principal axes can be viewed in the General Analysis 3D view. There is also a separate Moment Tensor window with a number of stereonets and mechanism charts. Two new training videos have been uploaded to the General Analysis (3D View) page that walkthrough the new tools.
The isosurfaces for b-value have been upgraded in the latest root. There is now much more control over the isosurface levels. Up to 5 iso's can be plotted for user defined ranges.
The root upgrade that coincides with the software upgrade beyond v5.9 includes a new app for creating and exporting models of mine geometry. Stope, cave and development geometry is a fundamental aspect of most geotechnical analysis. Mine geometry also varies over time and capturing these changes is critical in any back analysis or numerical modelling that investigates stability or monitoring parameters over time.
We have started rolling out a new version of the mXrap software and root folder. Software versions 5.9 and above include a few interface changes. The new version is available on the download site but DO NOT download it until someone from the mXrap team has upgraded your root folder. Several root folder changes need to be made simultaneously with the software upgrade. We will be in touch soon to arrange the upgrade (if we haven't already).