SERVICES – OHMS

Tertiary qualifications: BSc + CDE, BSc Hons, M.Sc (Geology), GDE (Economic Geology), EDP
Specialization: Mineral Resource Management (MRM)
Professional affiliations: GSSA, SAIMM, SACNSP

Mr. Mbongeni Mabuza obtained his junior BSc and Education Diploma in 1986 from the University of Swaziland. He then enrolled for a BSc Geology (Honors) degree obtained in 1989 at the Scottsville Campus of the University of Natal in Pietermaritzburg (UNP).

He got his MSc in Geology in 1993 from UNP as well. He then enrolled for the GDE with Wits University and obtained the GDE diploma in 2006. In 2012 he obtained a diploma in Executive Development Programme (EDP) from UNISA.

His geo-professional career started in 1987 when he worked for the Swaziland Geological Survey and Mines Department as Field Geologist working on the Pongola Sequence field relations, geochemistry and petrology until 1992.

In 1993 he joined Rand Mines in Virginia; Free State, where he served as Junior Geologist at V1 and V2 gold producing shafts. In 1994 Mbongeni moved on and joined Anglovaal Mining who appointed him Section Geologist at Eastern Transvaal Consolidated Mines (ETC), at New Consort and Agnes Gold Mines in Barberton.

At the beginning of 1998, Mbongeni was moved to Allanridge, Free State where he joined the Target, Sun and Oribi exploration camp and also served as Senior Geologist in the development of the Target Gold Mine also for Aglovaal Ltd.

In 2001 he was appointed Chief Geologist for the Two Rivers Platinum Project near Steelport in the Eastern Bushveld Complex. In 2004 he became Geology Leader for the Two Rivers Platinum mine development for the ARM/Impala JV until the later part of 2006 after which he joined Redwing Mining Ltd as Geology Manager looking after and guiding the Mineral Resource Management (MRM) inputs at 5 producing gold mines in Zimbabwe until the global recession in 2008.

In 2009 he re-joined ARM as Geology Manager, a post he still holds to date.

Tertiary qualifications: NHD (Rock Eng.), CoM REC, CoM Adv. REC, GDE, M.Eng (RockEng.)
Professional affiliations: FSANIRE, MSAIMM, Pr.Nat.Sci

Koos is co-founder and shareholder of Open House Management Solutions (Pty) Ltd (OHMS) and currently serves as Managing Director. He has been involved in the mining industry since January 1987. Following experience in the production section of Hartebeestfontein Gold Mine, he started his career in Rock Engineering in April 1990. He worked in various capacities in rock engineering with large mines in South Africa until January 2000, when he co-founded OHMS.

Koos has extensive experience in the field of rock engineering and geotechnical engineering in mines. His experience extends to the commodities of gold, platinum, chrome, copper, nickel, cobalt, manganese, diamonds, coal, fluorspar and silica. These operations utilise a large variety of mining methods including strip mining, open cast mining, narrow scattered mining, deep and ultra-deep longwall and sequential grid mining, bord and pillar mining, block cave mining, sub-level open stoping and sub-level caving. He further has experience in a range of geotechnical environments such as metamorphosed, sedimentary, igneous, saprolitic and weathered sedimentary and tectonically deformed or contorted.

Tertiary qualifications: B.Sc, H.Ed, B.Ed, CoM SC, MBA
Professional affiliations: FSANIRE

Vlok is a Director and shareholder of Open House Management Solutions (Pty) Ltd (OHMS). After completion of a B.Sc and B.Ed, degrees from the University of Stellenbosch Vlok joined the teaching profession for a few years before entering the mining industry in 1997. Following training as a mine seismologist at ISSI (now IMS), he joined AngloGold in 1998. In February 2000 Vlok joined OHMS as a Seismologist at Hartebeestfontein Gold Mine. His career then turned towards seismological consulting from where he was able to successfully launch a 24/7 seismic monitoring and data analysis facility in South Africa. In 2015 he became involved in geotechnical instrumentation projects. Vlok is now considered a highly experienced geotechnical instrumentation consultant in the mining industry.

Vlok’s project typically includes the following:

Deformation-, closure- & stress monitoring
Seismic network design, commissioning, and maintenance
Stress monitoring and measurements
Instrumentation network design and layouts
Training in seismology, geotechnical instrumentation

Tertiary qualifications: B.Sc (Hon), M.Sc, CoM SC, CoM REC, CoM Adv. REC, GDE (Rock Engineering), MBA
Professional affiliations: FSANIRE, MSAIMM, Pr.Sci.Nat

Gerrit joined the mining industry in 1996 as a mine seismologist in the gold and uranium division of Anglo American. He was seconded to ISS International Ltd in the position of mine seismologist between 1997 and 2006 in various operations in commodities of gold, platinum, coal and diamonds. In 2007, Gerrit, joined Anglogold Ashanti in the rock engineering department. After qualifying as a rock engineer he was seconded to the projects division of Anglogold Ashanti and participated in projects aimed at optimization of design of previously abandoned mine areas that were prepared for re-mining. His work focussed on quantifying risk through numerical modelling.

In 2010, Gerrit joined OHMS, to head a start-up of a new business unit that focussed on geotechnical consultancy and numerical modelling. The purpose of the unit is to provide a specialized numerical simulation and geotechnical consultancy service to the other business units within OHMS as well as to clients. Since 2021, Gerrit focusses on new business development, consultancy work, and technical support for Map3D.

Gerrit’s projects typically included the following:

Remnant design in deep gold mines.
Fault slip on geological hazardous structures
Probability of failure and Monte-Carlo simulations of open pit and underground designs
Waste dump design
Open pit design
Geotechnical input in aerial rope way design
Pillar designs (shaft pillar, board and pillar, regional pillars)
Training in processing software and geotechnical design software to the industry
Feasibility studies on various levels

Tertiary qualifications: NHD (Mining Eng), Mine Manager’s Cert of Comp, CoM REC, AREC, GDE (Rock Engineering)
Professional affiliations: FSANIRE, MSAIMM

Marius Stander joined the mining industry in 1998 as a learner production official and subsequently furthered his career by qualifying as a rock engineer. During his employment with AngloGold Ashanti he worked on various operations with majority of his time spent on Tau Tona and Mponeng mines in the Carletonville area. He participated as a main contributor on a strategic project for Anglogold and also published a paper in capacity of main author entitled “The Effectiveness of Splitsets as primary support at Mponeng Mine” at the 2006 SANIRE Symposium. He also conducted work and is co-author of a paper named “Fractures around stopes in the Wits and BIC”.

Marius joined OHMS in November 2009 and he was appointed as Business Unit Manager responsible for the Operations of OHMS in the North West Business unit. During 2012, he was contracted by TWP Projects as the project manager of a Pre-Feasibility study on one of the AngloGold Ashanti Mines in the Vaal River Region. Since 2012, Marius have been involved in junior miner’s operations of aggregate and diamond quarries and pits to compile their relevant Codes of Practices and provide routine geotechnical services. Further he was involved in the Development of a New Board and Pillar Mine in the Northern Cape.

Since 2014, Marius was involved internationally on various projects countries, such as, Zimbabwe, Zambia, the DRC and Burkina Fasso. The projects dealt with geotechnical systems audits, assess and advise on staffing requirements, development site specific Geotechnical Training Lesson Plans and relevant training aids. Further Marius was involved in the collection, processing and interpretation of Geotechnical data to provide input on Geotechnical design projects and development of ground control management plans.

From 2016 to 2021, Marius was examiner for the Chamber of Mine Certificate in Rock Mechanic, Specifically dealing with Papers 2 and 3.1.

Marius’ experience base ranges from low stress shallow mining operations to Deep Level high stress mining.

His other areas of operational and technical expertise include:

Site investigation and material characterisation;
Design of excavations and geotechnical monitoring;
Risk assessment;
Support layouts and design for normal and abnormal conditions;
Drafting of COP for surface and underground mines;
Surface and underground Pre-feasibility and bankable studies;
Day to day managing of Rock Engineering services for clients.

Tertiary qualifications: CoM SCO, CoM REC, AREC
Professional affiliations: FSANIRE, MSAIMM

Quintin is a Senior Geotechnical Engineer and heads up the Numerical Modelling and Consulting division of OHMS at the Head Office in Potchefstroom. Quintin has been involved in the field of rock mechanics and geotechnical engineering since 2010, and have experience in a vast amount of mining methods and commodities in South Africa and Africa. Quintin and his division, specializes in various levels of studies on the geotechnical aspects of, inter alia, open pit stability, tabular and massive mine design, pillar design and support design.

Tertiary qualifications: CoM SCO, CoM REC, CoM Adv. REC
Professional affiliations: FSANIRE, MSAIMM

André has been involved in the field of rock mechanics and geotechnical engineering since 2000. In 2004 he opened OHMS’s first regional office at Lydenburg. During his career with OHMS he has worked at various client’s operations practising at a range of technical, strategic and operational levels. During his career in rock mechanics, André has gained experience in the commodities of chromitite, platinum, copper, gold, coal, pegmatite (in the form of quartzite, feldspar, silica and mica) and diamonds. He is currently the operations manager in the Eastern Bushveld and his specialities (for both underground and surface mines) include:

Site investigation and material characterisation
Design of excavations and monitoring of their performance
Risk assessment
Fall of ground investigations
Open pit design
Pillar designs (shaft pillar, board and pillar, regional pillars)
Strata Control and Rock Engineering-related training
Design of excavations and geotechnical monitoring
Support layouts and design for normal and abnormal conditions
Drafting and auditing of COP for surface and underground mines
Day to day managing of Rock Engineering services for clients
Third party systems audits

Monitoring & Verification

• Design, installation and operation of rock mass response monitoring systems.

○ Design and installation of seismic monitoring networks.

○ Processing and analysis of seismic data to quantify seismic hazard.

○ Design and installation of stress and deformation monitoring systems.

○ Processing and analysis of stress and deformation data.

○ Design and review of slope stability monitoring programs.

• Independent system audits and verification.

• Accident and failure investigations and root cause analysis.

• Third-party reviews and opinions for purposes of legal proceedings, loss adjustment and investment decision-making.

• Project gap analysis.

• Blast vibration monitoring and quantification of peak particle velocities (PPV’s).

• Back Analyses and Design vs Response correlation.

Design

We leverage cutting-edge technologies and adhere to industry-accepted methodologies to quantify the parameters essential for creating a stable mine design.

Designs include:
• Stable stope dimensions and geometries.
• Optimal exploitation layouts and sequencing.
• Mine access and service excavation layouts.
• Local and regional support pillar design.
• Backfill design and specification.
• Design of safe and economical excavation support layouts.
• Seismic hazard quantification and rock burst amelioration.
• Stable slope design on overall, inter-ramp and bench scale.
• Design of rock fall protection strategies.
• Waste rock dump design and stability assessments.
• Quantification of factor of safety and probability of failure of various aspects of the design.

To aid design, we make use of the following software programs:
• Gem4D (BasRock)
• Trajec3D (BasRock)
• Slide2 (Rocscience)
• RS2 (Rocscience)
• RS3 (Rocscience)
• Dips (Rocscience)
• CPIllar (Rocscience)
• RocPlane (Rocscience)
• RocTopple (Rocscience)
• UnWedge (Rocscience)
• SWedge (Rocscience)
• MAP3D
• Jblock

Specification & Implementation

From comprehensive designs we detail all parameters typically required by mining engineers to design a safe and sustainable mining operation.

We participate in the recording and communication of vital specifications trough the compilation of:

• Baseline and Issue-Based Risk Assessments.

• Codes of Practice (COP).

• Ground Control Management Plans (GCMP).

• Standard Operating Procedures (SOP’s).

• Trigger Action Response Plans (TARP).

Analyses & Interpretation

Analyses and interpretation are focused on:

• Describing and quantifying appropriate strength and failure criteria.

• Construction of geotechnical databases and block models.

• Construction of structural models.

• Description of statistical variability for point estimate and Monte Carlo methods.

Data Collection & Quantification

Considering the unique circumstances of each project, we craft a tailored data collection program that will yield adequate parameters to describe the geotechnical aspects of the rock mass. Our data collection programs typically include a combination of the following methodologies:

• Geotechnical core drilling and core logging.

• Scanline and face mapping.

• Laboratory testing of mechanical properties.

• Ground Penetrating Radar (GPR) scans.

• Lidar and photogrammetry images.

• Acoustic and Optical (ATV and OTV) televiewer wireline scans.

• Borehole camera observations.

• Rock mass deformation monitoring results.

Tertiary qualifications: B Com Law (Acc), B Com Honn (Fin Acc), M Com (Man Acc), SAIPA, PCA
Specialization: Financial & Management Accounting

Lorette started her career at Erasmus Accountants in Pretoria, where she qualified as a Professional Accountant in 2006 with the South African Institute for Professional Accountants (SAIPA). She then advanced her career as an Accountant at Rappa Holding (Pty) Ltd in 2007, where she gained her first experience in mining related activities. She joined the Living Gold (Pty) Ltd team later in 2007. At Living Gold she was Senior Accountant. In 2009 she accepted the position as Financial Manager at The Blue Group where she worked until 2012, where after she re-joined the team of Living Gold as Financial Manager. She further qualified as a Payroll Certified Administrator (PCA)(2010) and completed her Masters degree in Management Accounting (2019).

Lorette is currently the Financial Manager of OHMS and also the appointed company secretary.

She has experience in:

Payroll
Management & Cost Accounting
Financial Accounting
Import & Exports
Financial reporting
Internal Audit
Policies & procedures
Taxation
Budgets & Forecasts
Withholding Tax

OUR GEOTECHNICAL ENGINEERING SERVICES INCLUDE: