Daniel John Avutia, South Africa
Daniel is a Masters in Geotechnical Engineering professional with 5 years' experience in the mining and infrastructure sectors. He has excelled in the construction and mining industries with notable achievements such as being a finalist for the South African Institute of Civil Engineering (SAICE) Young Engineer of the Year Award, SAICE JE Jennings Award and being selected to represent Africa at the International Society for Rock Mechanics (ISRM) Rockbowl competition. Daniel has presented at international and national engineering conferences with technical publications on three continents.
Daniel's desire to succeed in the resources and infrastructure sectors has been ignited through his exposure to potential investment opportunities for future growth in Africa, namely filling the infrastructural gap and promotion of domestic beneficiation of African commodities. Daniel is an avid traveller and has recently visited all 6 continents through his passion for engineering and sport.
Analytical study of sinkhole propagation in South Africa
Karst landscapes cover 15% of the earth's topography with an estimated 1.5 million inhabitants residing on the land. Therefore restricting land uses and avoiding mineral exploration on the sinkhole prone karst geology may be deemed highly impractical. The occurrence of sinkholes in karst geology has encouraged engineers into developing geotechnical models to simulate the magnitude of subsidence. Sinkholes encompass the withdrawal of shallow sediment into deep hollow compartments located in karstic stratum. Sediment withdrawal is triggered by the alteration of the existing groundwater level which erodes weathered altered dolomite (WAD) residuum into cavities. Substantial literature has explored the stability of strata above sinkholes, relying on empirical data and limit analysis, to quantify the strength of the porous karst residuum.
This study appraised the propagation of dolomite sinkholes through the incorporation of Terzaghi's arching in soils equation, which determined the angle of draw of karst overburden layers. The analytical results illustrated constant vertical drawdown in the WAD residuum and incremental cavity propagation in the frictional chert residuum.