MEASUREMENT AND SIMULATION OF LOW FREQUENCY IMPULSE NOISE AND GROUND VIBRATION FROM AIRBLASTS

• Published in: Journal of sound and vibration 1998-07, Vol.214 (2), p.309-324
• Main Authors: Hole, L.R., Kaynia, A.M., Madshus, C.
• Format: Article
• Language: English
• Subjects: Acoustics; Aeroacoustics and atmospheric sound; Aeroacoustics, atmospheric sound; Applied sciences; Buildings. Public works; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Geotechnics; Physics; Soil mechanics. Rocks mechanics
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1006/jsvi.1998.1562

This paper presents numerical simulations of low frequency ground vibration and dynamic overpressure in air using two different numerical models. Analysis is based on actual recordings during blast tests at Haslemoen test site in Norway in June 1994. It is attempted to use the collected airblast-induced overpressures and ground vibrations in order to asses the applicability of the two models. The first model is a computer code which is based on a global representation of ground and atmospheric layers, a so-called Fast Field Program (FFP). A viscoelastic and a poroelastic version of this model is used. The second model is a two-dimensionalmoving-loadformulation for the propagation of airblast over ground. The poroelastic FFP gives the most complete and realistic reproduction of the processes involved, including decay of peak overpressure amplitude and dominant frequency of signals with range. It turns out that themoving-loadformulation does not provide a complete description of the physics involved when the speed of sound in air is different from the ground wavespeeds.