Design of rocket tunnels. Phase 11

In order to study the propagation of blast wave in tunnel systems, a project started 1995 with tests in full scale and model scale. The full-scale test has been performed in a rock tunnel at the shooting range in Älvdalen. In this phase (11) the effect of changes in tunnel areas were studied. The area changes were created by connecting steel pipes with different diameters and install them in the barrier in the existing tunnel system. The diameter used were 940, 600 and 310 mm. Both sharp and 1 meters transitions were use in both in decreasing and increasing the diameter. In this phase, only full-scale tests were performed. A charge of 125 or 625 kg of ANFO were detonated at different distances from the barrier.