Rapporteur's report, session 6: Noise in elevated structures; Vibration propagation; Vibration isolation techniques
✍ Scribed by D.E. Newland
- Publisher
- Elsevier Science
- Year
- 1977
- Tongue
- English
- Weight
- 146 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0022-460X
No coin nor oath required. For personal study only.
✦ Synopsis
Dr Leonard Kurzweil's introductory talk ranged over a wider field than his prepared paper, covering many aspects ofground vibration transmission and methods for vibration isolation. He paid particular attention to ground vibration caused by underground trains and the effectiveness of floating slab isolation systems [1,2].
Dr Kurzweil presented data on tunnel wall vibrations for different rail fasteners and ballast and data on vibration levels measured underground and on the surface at different distances from the track. He suggested that ground vibration levels could be reduced by (i) reducing wheel-rail roughness, (ii) reducing unsprung mass, (iii) using resilient rail fasteners and, particularly, (iv) by the adoption of floating slabs. Measurements on the experimental floating slab track in New York has shown approximately 20 dB noise reductions in the 63 and 125 Hz octave bands, although there had been a slight increase (6 dB) ir/the floor vibration level in the 16 Hz octave band due, apparently, to resonance of the floating slab on its supports. Dr Kurzweil concluded his presentation by raising the following questions which he felt could not yet be answered satisfactorily.