Title Study of the wavefield generated by a gas exploder used for artificial avalanche release
Author Suriņach, E.; Vilajosana, I.; Kleemayr, K.; Rammer, L.
Author Affil Suriņach, E., Universitat de Barcelona, Departament de Geodināmica i Geofísica, Barcelona, Spain. Other: Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Austria
Source Cold Regions Science and Technology, 66(1), p.17-29, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0165- 232X
Publication Date Apr. 2011
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 309483
Index Terms sound waves; avalanches; elastic waves; explosives; geophysical surveys; mass movements (geology); seismic surveys; slopes; snow; surveys; velocity; seismic velocity; Austria--Obertauern; acceleration; acoustical waves; artificial release; Austria; body waves; Central Europe; Europe; explosions; frequency; Gamsleiten; Gazex(R) device; geophysical methods; mass movements; Obertauern Austria; P-waves; seismic methods; seismic sources; seismic waves; wave amplification; wave fields
Abstract A study of the entire wavefield (3D) generated by the detonation of a Gazex(R) device performed on the Gamsleiten slope, at Obertauern, Austria is presented. The main aim of the study was to determine whether the detonation can trigger snow avalanches in remote locations. A linear array of sensors in the vicinity of the blasting point combining six 1D and two 3D seismic sensors was deployed. Three independent Gazex(R) detonations were subsequently triggered in intervals of approx. 15 min. The signals obtained were similar. Waves propagating through the ground (P waves) and sound waves were clearly detected. The corresponding ground velocities and accelerations were determined. The frequency content of the whole signals was band-limited to 10-40 Hz, although the frequency content of P waves was lower than that of sound waves in the three components. A different behaviour in the frequency content evolution of the two wave groups was observed. P waves suffered distortion and attenuation with distance. This was not observed in the sound waves which showed local amplifications. The maximum values of the velocity and acceleration measured correspond to the sound waves observed in the horizontal components. The values of the ground accelerations obtained for the whole signals were 6 times lower than the value of the critical acceleration, which is the value that is required for the inclined snow slab to be stable. Cumulative snow slab displacements caused by long vibrations were also considered. The results suggest that in this case the likelihood of a snow avalanche release due the Gazex(R) device detonations is low. However, this result cannot be generalized to other snow and terrain conditions and to other conventional explosives. Specific studies should be carried out at the target sites/situations. Another important finding was the significant contribution of the horizontal components to the ground movement. This indicates that it is necessary to consider the whole wave field (3D) in this type of study.
URL http://hdl.handle.net/10.1016/j.coldregions.2011.01.002
Publication Type journal article
Record ID 65006624