Drilling holes, filling them with explosives, detonating them, removing the debris, inserting supporting material, measuring and then doing the whole thing again from the beginning: this is how the advancing method "Drill and Blast" can be roughly defined.
Despite the frequent use of tunnel boring machines (TBM), this conventional method of driving is still widely used today. For this reason, a place like the Hagerbach Test Gallery is needed, which offers the unique opportunity to develop innovations and test them in a realistic environment.
The test gallery was also excavated by drill and blast driving and has grown over the years to over 5.5 kilometres. With this growth, a large number of technologies and procedures have also been tested and improved. From a historical perspective, the tunnelling technology involving drilling and blasting can be classified between the traditional "hammer and chisel" and mechanized tunnelling methods such as TBMs.
At the beginning of the test gallery, the Swiss Industrial Company SIG as a shareholder also tested its products in the facility. As proof of the robust design and durability of the equipment even under difficult operating conditions, one of the drilling devices developed at that time is still used in the test gallery today.
Even today, the conventional driving method still has its raison d'être. Rock hardness, driving lengths or other specific environmental conditions in mining, tunnelling or special civil engineering require the use of the best possible technology. In the Hagerbach Test Gallery, various mining machinery suppliers are therefore testing, comparing and subsequently improving methods, machines and variants.
An essential differentiation of the blasting method compared to the mechanized methods is the discontinuity of the individual process steps, which have to be carried out one after the other and separated in time. The optimization of the different steps, as well as their totality, will continue to be an important area of responsibility for the "Innovation and Training" unit of the Test Gallery in the future.
Thus, the tunnel system will continue to expand, blast by blast, using ever more intelligent machines and processes.
"Over the last 50 years, we have acquired a great deal of know-how in the field of "Drill and Blast" in the Hagerbach Test Gallery, with which we can accompany your project and lead it to success," says Erich Lassnig, Head of Innovation & Training.