BlastWeb Case Studies
DetNet’s BlastWeb and SmartDet Used for Gautrain Project
Application:15 Kilometres of underground tunnels excavated under sensitive, built up areas in and around Johannesburg CBD. There were also time and environmental impact constraints associated with blasting. In some instances blasting had to take place as shallow as 15m below the surface.
Location: Gauteng, South Africa
Product: DetNet’s BlastWeb / SmartDet Electronic Delay Detonators
Solution: Bombela Civils Joint Venture, part of the Bombela Group, is responsible for the design, build, part finance, and marketing of the system for a 20 year period. Bombela CJV is responsible for the design and implementation of the civil works component of the Rapid Rail Link. AEL Mining Services was awarded the tunnelling explosives and initiating systems supply contract, offering two market leading technologies. These included BlastWeb / SmartDet(designed by DetNet), which are robust, flexible and user friendly initiating systems and R100G, which is a safe and efficient Underground Pumpable Bulk Emulsion explosive.
The tunnelling route includes 4 stations and 7 emergency shafts varying from 6 to 21m in diameter and depths between 35 to 90m. Considering the majority of the Gautrain stations being situated in close proximity to high value properties such as Sandton and Rosebank, the initiation and blasting system had to minimise air blast and ground vibrations. The blasting was executed with minimal interruption to business and residential areas.
The blasting and tunnelling has been done through two different rock formations, namely Granite and Witwatersrand, a heterogeneous ground composed alternatively of quartzite, siltstone, shales and andesites in various degrees of weathering. To minimise air blast and vibrations, SmartDet, DetNet’s fully programmable electronic initiating system, was used for the shaft sinking and the BlastWeb for the tunnelling.