Recently Completed Projects
SCPTu testing for geotechnical parameters.
Our team oversaw the SCPTu testing at various facilities where we are the Engineer of Record. SCPTu testing was conducted at predefined probe positions and the results of the testing was analysed to calculate the relevant geotechnical parameters and pore water pressure profiles. These results were then used in slope stability assessments for the facilities. As SCPTu provides reliable and consistent results we prefer to use this technology for soil profiling.
Trade-off study for coal discard site.
Our team provided specialist tailings dam engineering support to a Coal Discard Facility Prefeasibility Study in Mpumalanga, South Africa. Several site locations were assessed to ensure that the optimum sites were chosen. Thereafter, a trade-off study was presented incorporating the slope stability, placement methodologies, stage capacities, operational requirements, operational readiness, liner design and capping design of the best two sites. A whaleback design was recommended over a benched design, mainly due to the lower spontaneous combustion risks.
Alternative Class C containment barrier to reduce cost and improve constructability
Geotheta designed an alternate Class C containment barrier for two TSFs in Free State, South Africa. The alternate barrier system reduces seepage by ensuring that flow through any holes in the liner behaves as D’Arcian flow instead of Bernoulli flow. The stability of the TSF is also improved by omitting lower strength compacted clay layers and the geomembrane cushion layer. Overall, the alternate barrier system resulted in a large savings for the client and improved constructability.
Deposition modification to extend life of a facility.
In Springs, South Africa, the Geotheta team designed a conversion from daywall paddock deposition to cyclone deposition that allows the existing facility life to be extended and overall capacity to be increased. The project will transform the current facility to a cyclone-operated system and also ensure the facility complies with the latest international standards. The TSF will be buttressed and developed in an upstream manner with coarse cyclone under flow material placed on the outer slope and the fine overflow material contained within the formed basin
Flood risk assessment for a mine’s process water dam
Geotheta recently conducted a flood risk assessment for a coal mine in Mpumalanga, South Africa. Our engineers assessed the credible failure modes at a process water dam and then modelled a breach on one flank of the dam. The peak flow was calculated at multiple points within the zone of influence so that our engineers could assess whether the flood would exceed the capacity of existing infrastructure. The client gained an understanding of the impact of a breach, specifically to the mine’s production conveyor belt situated downstream from the dam.
Feasibility design for iron ore tailings dam and waste rock dump
Our team provided specialist geotechnical and tailings dam support for an iron-ore mine feasibility study in KwaZulu-Natal. The new TSF was designed to safely accommodate the iron ore tailings from the plant for 30 years. Work included the required geotechnical and hydrotechnical assessments. The study included a tailings deposition dry-stacking trade-off study.
Dirty water management design for a colliery
Our team evaluated potential flooding risks and developed a plan to keep polluted water and clean storm water separate at the Leeupoort Colliery close to Delmas, Mpumalanga. Work included the required hydrology and flood risk assessments. All stormwater trenches and diversion bunds were designed accordingly. A stockpile liner system was designed and stabilities and liner forces were assessed. A daily stochastic water balance model was developed and a pollution control dam was included to contain the required volumes. Detailed engineering reports, drawings, specifications and Construction Quality Assurance plans were prepared for submission to Department of Water Affairs for licensing purposes.
On-site SCPTu testing, analysis of results and slope stability assessments
Geotheta was commissioned to conduct SCPTu testing and assess the possibility of future deposition on multiple dormant facilities for Harmony Gold. On-site SCPTu testing was done to determine the tailings and foundation geotechnical paramaters. Thereafter, slope stability analysis was conducted by modelling the facilities at current and future heights. Geotheta recommended against future deposition and proposed remediation measures to improve the safety and compliance of the facilities.
Conversion of TSF facility from day-wall to impoundment to comply with ICMM/GISTM requirements
Geotheta assessed the stability of a silica facility according to internal tailings management standards for a member of the International Council of Mining and Metals. Following the assessment Geotheta recommended options to ensure the facility complies with the required Factors of Safety. The chosen option was to convert the facility from a day-wall system to an impoundment. This work will be carried out across phases to reduce upfront project costs.
Feasibility design of gold tailings dam mega-project
We conducted a feasibility level design for a 93m high, 804 million tonnes, gold tailings facility and associated infrastructure in Free State, South Africa. Due to the height of the facility a cost-effective solution was required to reduce high liner stresses. Furthermore, 2-phased deposition strategy was designed to reduce the required height of the starter wall.
Detailed design of a tailings and waste-rock co-disposal facility
Geotheta recently designed a tailings and waste rock co-disposal facility, including “Issued for Construction” drawings and budget pricing. Work included analysis for the optimum tailings/dump rock mixture volumes, assessment of underground workings stability, design of the appropriate regulated liner configuration, final height slope stabilities and a pollution control dam. We also supported the client to attain the necessary licence approvals.
