Noise emission and noise protection from HS Rail Mr Mats Hammarqvist & Anders Frid

Transcription

1 Noise emission and noise protection from HS Rail Mr Mats Hammarqvist & Anders Frid Trafikverket seminar 3 June 2014

2 Noise and vibration from trains Anders 2 Generation / emission Mats Propagation/reception

3 European legislation TSI (Rolling stock) NOEMIE campaign - European high speed trains (final report 2005) Current TSI Noise limit values expected to remain unchanged in upcoming revision 2014/2015!

4 Noise sources Wheel-rail Cooling fans and equipment Aerodynamics 4

5 Rolling noise Contact surface unevenness create vibrations that radiate noise Maintenance of wheels and track is crucial to keep low noise levels TWINS - Dedicated calculation tool for rolling noise (can handle both ballast and slab track)

6 Important parameters for high speed trains Rolling noise Speed Wheel and rail surface conditions Track stiffness (pads and resilient elements) Wheels (size, shape, damping) Aerodynamic noise Speed Protrusions and cavities

7 Noise reduction at the source Rolling noise generation Maintenance (reprofiling, grinding) of wheels and rails Damping on wheels and rails Aerodynamic noise generation Smooth surfaces (no cavities or protrusions) Leading bogie covered, no pantograph on leading car Noise radiation Close shields (trackside low barriers + vehicle skirts)

8 Track properties influencing noise Main differences: Stiffness (stiffness distribution) Slab track typically has softer rail pads to compensate for the flexibility of the ballast Softer rail pads causes the rail to radiate more noise Acoustic absorption Slab track surface typically has lower absorption than ballast surface slab surface can be fitted with absorbents Low surface absorption reflects more noise to the wayside Source: Getzner Consequences: Sound radiation from rails Sound absorption of slab surface Roughness/corrugation growth SNCF study 2013: +1 db +1 db +1 db +3 db

9 The importance of elasticity Rail pad Rail pad stiffness influences mainly noise (>100 Hz) Under-sleeper pads, ballast mats and slab mass spring systems influences mainly ground-borne vibration (<100 Hz)

10 Surface absorption Acoustic absorbents to improve performance of slab track Absorptive panels

11 Ground-borne vibrations Complicated to model wave propagation in the soil Large uncertainty in input data Important parameters Train speed Axle load and unsprung mass Wheel out-of-roundness Rail corrugation Soil properties Mitigation measures Track stiffness (under sleeper pads, ballast mats, mass spring systems, ) Ditches, blocking masses, etc NB! Conflict between low noise and low vibration track (pad stiffness) 11

12 Highspeed Railways Impacts and consequences

13 Impact Facade/Window->indoor noise

14 Swosch. Not swisch!

15 Consequence windows/facade/indoor

16 Simplified consequence facade

17 Impact / facade / Window -> indoor noise 3-pane window R w = 40 db C = -2 C trafik = -9 C X2000 = 0 C VHS350km/h = -4

18 Buildings - Norway Wooden buildings 2-pane windows Inlets in window Brecke & Strand, 2011

19 Sum up Higher speed with aerodynamic noise (low frequency) -> better facade insulation needed X2000 better facade-insulation than ordinary train The spektra of sound insulation matters (heavy glass better low frequency) No consistency between investigations

20 Vertical position source/railway

21 Sound Paths

22 Source Height Calculation Model NMT Maximum height 2 metres

23 US & Germany

24 3 meter noise reduction screen ÅF 2014, test new in house calculation method

25 5 meter noise reduction screen ÅF 2014, test new in house calculation method

26 Experience - Netherlands

27 Sample dutch

28 Source Strength Ranking Speed [km/ 320 Rang diff max Source height sel mph k km/h SEL at speed Propulsion wheel - rail train nose wheel region Pantograph SEL Propulsion wheel - rail train nose wheel region Pantograph

29 Indoor Effect Noise Consequence (?) High screens Norway, Brecke & Strand, 2011

30 Landscape Bridges - NMT Både höjd och emission? Emission:

31 Different bridgetypes own data Brotyp Ljudnivåskillnad, db(a). 1. Broar helt i stål utan ballast +8 till Stålbroar med ballastfyllning och underliggande bärande låd- eller I-balkar +1 till Ballastfyllda betongtråg på underliggande bärande lådbalkar av stål +1 till Ballastfyllda betongtråg på underliggande bärande I-balkar av stål -4 till Ballastfyllda betongtråg mellan bärande höga I-balkar av stål (avskärmande) -5 till Ballastfyllda helbetongkonstruktioner -1 till +3

32 Slab track - bridges David Thompson, ISVR, Southampton, Storbritannien

33 Verkehrslärmschützverordnung 16.BlmSchV (2012)

34 Example showing influence height of bridges

35 TGV 250 km/h ÅF 2014, test new in house calculation method

36 Calculation Sound levels Last time up to 200 km/h with X2000 (ruler method)

37 Speed dependence US transit federation Méthode et données d émission sonore pour la réalisation des études prévisionnelles du bruit des infrastructures de transportferroviaire dans l environnement ( km/h) NMT Nordic Model Frekvensberoende: ganska invecklad Ca 27*log(v/v0) för X2000

38 NMT Nordic Calculation Model

39 Tp - EN ISO 3095:2005 (E) SNCF, 2007

40 Maximum Level?

41 Twice as long 145 km/h 290 km/h

42 On-Set rate

43 Structure borne sound Speed dependance On the basis och measurements and calculations we have concluded these speed dependencies: 20*log(v/vref) between km/h 10*log(v/vref) between r km/h 18*log(v/vref) between r km/h Constant over 320 km/h ÅF 2010

44 Safety distance Structure Borne Sound 80 km/h 200 km/h 320 km/h safety distance 1 1,6-2,2 2,0-2,8