This case study shows how a unique combination of field measurements and advanced technologies allowed detonators to design, load and fire an incredibly challenging quarry explosion.
A natural limestone arch attached to a karst and heterogeneous cliff 120 meters (394 feet) high, dominated a new crushing plant in a quarry located in southern France.
Several blocks have already fallen and a large fracture located just behind the weakest point of the arch makes site administrators fear that the worst may happen. As is often the case in Western Europe, residential areas and sensitive roads surround the quarry at a very close distance. Only 70 meters (230 feet) separate the first house from the top of the arch.
An unexpected collapse of the arch put the personnel and the installation at risk. The next winter season and subsequent freeze and thaw cycles could have been a trigger, so time was also at stake.
In addition, the blasting of the arch without causing instability in the surrounding banks was essential for greater and safe access to the deposit.