ABSTRACT

Crush pillars are used as part of the stope support in intermediate depth tabular mining stopes. Crush pillar design should ensure that the pillars crush when formed at the mining face. This behaviour of the pillars is typically achieved when the pillars have a width to height ratio of approximately 2:1. Once crushed, the residual stress state of the pillars provides a local support function.

Dear Members
 
Please follow the link to the latest quarterly newsletter. Stories and articles are always welcome. Please email Paul Couto at Paul.Couto@Harmony.co.za for enquiries.

Download the PDF version: pdf SANIRE Newsletter Volume 2 Issue 3 July 2016 (3.95 MB)

My son Lihan has just turned 2 and every day I am astonished at how he is able to absorb and adapt to his surroundings. Although he is entering the “terrible twos” and verbally expresses his frustration with life, we need to understand that he is struggling between his reliance on us as parents and the desire for independence. At this stage, he absorbs everything said and done around him, and also acts this out. The photograph above was taken at Raka Winery. While I was tasting wine, he was tasting the corks. Whether this was a hint for food or a way of sampling the wine remains a mystery.

In our working environment, we typically form ourselves based on our mentors, managers, their work ethic, and strengths and weaknesses. In some cases, this allows us to thrive and excel in what we do. However, in some areas, mentorship is a luxury and a Rock Engineer could be operating on an isolated operation. As a result, he or she can only rely on his or her own experience and expertise.

On many operations, the design and layout parameters were put in place many years ago and by “respected” Rock Engineers. Consequently, we presume that these designs are correct and cast in stone. However, in this lies a flawed approach. Although these designs were adequate at the time, we have to challenge their continued applicability, based on our knowledge of the environment, new research findings, technology, methodologies and best practices.

I would want to equip my son Lihan with tools which will provide him with the ability to grow and recognise the strengths, weaknesses, limitations and opportunities in every situation. At some stage in his life, he will value the example set by his parents, but will start to mould himself on a new set of criteria, whether it be a role model or his environment. As Rock Engineers, we have the choice to continue to use a copy-and-paste approach (monkey see monkey do) or we can equip ourselves with the necessary tools to ensure that we excel. As Engineers, we should design for purpose, optimise designs and eliminate risk.

Michael du Plessis - SANIRE President

 

ISRM International Symposium

‘Rock Mechanics for Africa’

See event page: http://www.saimm.co.za/saimm-events/upcoming-events/afrirock-2017

Dates: 02-07 October 2017

Venue: Cape Town Convention Centre, Cape Town, South Africa

The 2017 ISRM International Rock Mechanics Symposium is to be held in Cape Town. The conference theme is “Rock Mechanics for Africa”.

Prior to the conference, the ISRM Board, Council and Commission meetings will take place. Technical visits are being arranged for after the conference.

37th Technical Evening, 30 June
WITS School of Mining
New Concept Mining

A very successful technical evening was held by SANIRE’s Gauteng Branch on 30 June 2016 at WITS University’s Digital Mine facility, in conjunction with New Concept Mining. Prof Fred Cawood and his team of postgraduate students facilitated the event in the superb mine design laboratory, which was put together through sponsorship from Anglo American. Two talks were presented; the first talk was by WITS postgrad student, Prince Mulenga (SRK) on coal squat pillar design using numerical modelling, followed by Prof Cawood’s overview of the WITS digital mine facility and of the state of the art in mining technology, as well as of history and a vision for the future.

A Strata Control Mini Symposium was organised and held by the SANIRE Free State Branch at Diggers Inn in Welkom on the 9th June 2016. The day was opened with a keynote address from the SANIRE President, Mr Michael Du Plessis.

The following presentations were presented on the day during two sessions which were led by Dr Jaco Le Roux and Mr Paul Couto:

Full Name: Riaan Carstens

Position: Manager Rock Engineering

Company/Organisations: Anglo Platinum

Date and Place of Birth: 31 August 1968, Kroonstad

Education: BSc and MSc in Mining Engineering

First Job: Stated in production as a graduate in training.

Personal Best Achievement/s: Obtaining my MSc, getting a million fatal free shifts at Mponeng Mine, surviving parenthood so far.

Philosophy of Life: Always try to leave things in a better position than what you found them.

Favourite Food/Drink: Oxtail potjie and good red wine.

Favourite Sport: Cycling

gerberFull Name: Jacques Dewald Gerber

Position: Head of Seismological Services (Africa)

Company/Organisations: Institute of Mine Seismology (IMS)

Date and Place of Birth: 7 March 1988, Port Elizabeth

Education: MSc (Physics)

First Job: Seismologist at IMS

Personal Best Achievement: Completing my MSc

Philosophy of Life: Vivite Fortes (live courageously)

Favourite Food/Drink: Pizza

Favourite Sport: Soccer

Vivite Fortes (live courageously)

How did your career in the mining industry begin and where are you now?

I joined the mine seismology group at IMS after completing an MSc (Physics) at the Nelson Mandela Metropolitan University. I have been involved in providing routine seismological services to the mining industry since 2012, and I was appointed as manager of the South African Seismological Services Group in 2015. During the past two years, I have also been responsible for the development of numerical modelling software.

hist5A change so unexpected, and a development never known before, followed from the discovery in 1886 of the greatest gold mines of all history, ancient and modern. From 1886 (until 1940), the story of South Africa is the story of gold – C.W. de Kiewiet, 1941. The discovery of gold on the Witwatersrand in 1886 was a turning point in South African history. Far more than diamonds, this led South Africa from an agricultural society to become the largest gold-producer in the world. Gold increased trade between South Africa and the rest of the world. For the main trading nations, i.e. the Europe and the United States, gold was of value because their currencies were backed by gold. This was known as the gold standard. Under the gold standard, these countries had to keep gold in a bank vault to the value of the currency they issued. For example, if the government of a country wanted to print more money, it had to buy gold to back that money. If that country did not produce gold itself, it had to import gold from another country. Under the gold standard, the price of gold was fixed internationally. It was kept low as this benefited nations in Europe, as well as the United States, amongst others. These strong nations did not produce gold and had to buy it from elsewhere to back their own currency. In the 1930s, many countries abandoned the gold standard. The effect that this had on the South African economy will be examined later on in this feature.

Dear Members
 
Please follow the link to the latest quarterly newsletter. Stories and articles are always welcome. Please email Paul Couto at Paul.Couto@Harmony.co.zafor enquiries.

Download the PDF version: pdf  SANIRE Newsletter Volume 2 Issue 2 April 2016 (5.41 MB)