The SANIRE Coalfields branch held its year-end function on the 02nd of December 2016 at the Tweefontein Recreation Club, in eMalahleni. This marked one of the very first events since the new branch committee was elected in February. A number delegates, consisting of practitioners, consultants and suppliers, came from various parts of the country to enjoy this prestigious event. The total number of delegates in attendance was 47 and the event was sponsored by Videx and Rocbolt technologies.

Rudiger Welf Olgert KERSTEN

Student No 7272848

A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy.

Johannesburg, September 2016


The design of stable pillars in mining is of fundamental importance not only in the Bushveld mines but in the entire mining industry. Wherever mining occurs, pillars will be formed at some stage, and it is essential to predict their behaviour. It is imperative to know whether they would burst, yield or remain stable. Although of major importance, the design of pillars still suffer from major drawbacks and weaknesses that affect the results in a fundamental manner.

In recent years, the advent of borehole imagery and the ability of computers to manage and process the much larger data sets involved, have revolutionised the mineral wireline logging industry.

A continuous, orientated, high-resolution representation of a borehole wall offers many advantages to the rock mechanics engineer. The data provides knowledge about geology, structure, fractures and stress orientation. Most of this knowledge might be gained by analysis of orientated drill-core, but that option has proved to be time consuming, imprecise and costly.

Please note that the closing date for the Rock Mechanics practical examinations will be 17 January 2017 and NO late entries will be accepted.

Dear Members,
You are invited to the Joint Symposium of ISRM Young Scholars’ Rock Mechanics Symposium (YSRM2017) and New Development in Rock Mechanics and Geotechnical Engineering (NDRMGE2017). Please note the following overview and please feel free to forward this information to anybody who might be interested.

  • Title: 2017 ISRM Young Scholars' Symposium on Rock Mechanics (YSRM2017) & 2017 International conference on New Development in Rock Mechanics and Geotechnical Engineering (NDRMGE2017) – An ISRM Specialized Conference
  • Organizer: Korean Society for Rock Mechanics (KSRM)
  • Sponsor: International Society for Rock Mechanics (ISRM)
  • Date: 10-13 May, 2017
  • Venue: Jeju Island, Korea
  • Important Dates:
    Abstract: 12 December, 2016 (Extended from 11 November, 2016)
    Extended abstract: 11 February, 2017
    Full paper to a special issue (optional): 11 June, 2017
  • Website:

Download the flyer


Dear Member
Attached, please find an invitation to the 9th South African Young Geotechnical Engineers Conference (SAYGEC) to be held in Durban, KwaZulu-Natal, 13, 14 & 15 September 2017


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

Download the PDF version:  pdf 2016 11 16 SANIRE Newsletter Volume 2 Issue 4
(12.12 MB)
Download the ePub version: default 2016 11 16 SANIRE Newsletter Volume 2 Issue 4 (109.66 MB)


At the SANIRE AGM held in August we shared some of the history of the pass rates achieved for the various papers of the Rock Mechanics Certificates. The pass rate being relatively low is, however, dependent on the candidates being experienced enough to understand the study material and knowing how to apply it in actual case studies or work situations. For most candidates, obtaining a Rock Mechanics Certificate is a true journey, comprised of highs and lows. There is no greater feeling of disappointment when you know that you have put in a lot of effort, yet you still fail a subject. I can recall the accomplishment I experienced when I “eventually” passed my ticket. We always hear our mentors and managers saying that we need to keep on trying; perhaps the next paper is your paper. Looking back, I can now also echo these words. Through your personal journey to obtain the qualification, you will also reach a point in your career when you will look back and realise that you only passed the ticket when you were prepared technically and had obtained sufficient experience to understand and apply the knowledge you had gained over the years. In South Africa we have achieved more than 100 qualified Rock Engineers in the past 5 years. Success is dependent on each person’s ability and effort. “Success is not final, failure is not fatal: it is the courage to continue that counts” (Winston Churchill).

The SANIRE AGM was hosted on the 9th September 2016 at Ruimsig Country Club, whereby the following awards were handed over to deserving members of SANIRE. The day was enjoyed by all who attended.

Full Name: Michael du Plessis

Company: Lonmin Platinum

Designation: Group Rock Engineering Manager

Qualifications: B.Sc., AREC, GDE, M.Eng., Ph.D.


Michael joined Anglo American Platinum in 2002 after graduating from RAU (now University of Johannesburg). He obtained his Rock Mechanics Certificate in 2005. From 2005 to 2007, Michael worked for Minova, servicing the mines, especially along the eastern limb of the Bushveld. In 2007 Michael joined Lonmin Platinum. He was appointed as the Group Rock Engineering Manager in 2009. He obtained his Master’s degree from the University of the Witwatersrand in 2009 and a Doctorate from the University of Pretoria in 2016.

SANIRE Free State Branch hosted there annual 2016 Year End Function at Goldfields Game Farm in Virginia on the 28th October 2016. the function started at 10:00 in the morning and included the members families. The families enjoyed a game drive, predator camp, swimming pool and kids play area with a jumping castle. A delicious spit braai was served for lunch while listening to a local live band. The day was enjoyed by all and was a huge success.

Recent developments

  • Rock Mechanics Principles, a video course by Prof. Jian Zhao. Available from the website.
  • ISRM Suggested Methods on video.
  • ISRM sponsored an investigation of the Nepal earthquake, chaired by VP He Manchao from China.

Board and Council meetings

The ISRM held its 2016 Council meeting in Ürgüp, Turkey, on 28 August, in conjunction with the EUROCK 2016, organised by the Turkish ISRM National Group. Out of the 60 National Groups, 49 were either present or represented. The Council was also attended by Past President Prof. Shunsuke Sakurai, Chairmen of several ISRM Commissions and a representative of the IAEG. Michael du Plessis represented South Africa and Omberai Mandingaisa represented Zimbabwe. William Joughin represented Tunisia on behalf of Essaieb Hamdi.

The ISRM board meeting was held on the 27th August and William Joughin represented the African region.

RangasamyFull Name: Trevor Rangasamy

Position: Director & Principal Rock Engineer

Company/Organisations: Middindi Consulting (Pty) Ltd (RSA), Middindi International Ltd, Rangkom Investments (Pty) Ltd

Date and Place of Birth: 11 September (911), Durban

Education: MSc (Eng), BSc (App Geology), AREC, COM Cert, SC Cert, G.D.E (Wits)

First Job: Assistant Strata Control Officer, Vaal Reefs Mining & Exploration Company

Personal Best Achievement/s: First Black COM Cert Rock Engineer in RSA, Starting Middindi Consulting (Pty) Ltd, making informed decisions whilst working on mines that saved lives

Philosophy of Life: Hard work never killed anyone ….

Favourite Food/Drink: A nice Durban bunny chow and Granadilla Twist

Favourite Sport: Cricket

rockstarFull Name: Quintin Lennox Grix

Position: Unit Manager – Rock Engineering

Company/Organisations: Goldfields, South Deep

Date and Place of Birth: 7 March 2016, Germiston, Johannesburg


First Job: HVAC Technician & SHEQ Consultant

Personal Best Achievement/s: Obtaining my REC at a young age!

Philosophy of Life: Today is the beginning of the rest of your life.

Favourite Food/Drink: Red wine & lasagne

Favourite Sport: Rugby!


Johannesburg’s early history is the story of gold. In 1853 Pieter Jacob Marais, a South African prospector, recovered alluvial gold from the Jukskei River, north of what would become Johannesburg. The years that followed brought several modest strikes, but the Witwatersrand Main Reef eluded searchers until 1886, when George Harrison, an Australian prospector, chanced upon an outcropping on a farm called Langlaagte. Ironically, Harrison failed to appreciate the significance of his find: he sold his claim for £10 and embarked for the goldfields of the eastern Transvaal region.


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 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:

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.