Noise emission and induced

vibration from heavy weapons

Timo Markula, Akukon Ltd

Mika Hanski, Akukon Ltd

Tapio Lahti, TL Akustiikka

European Conference of Defence

and the Environment ECDE 2015

Helsinki, 10.6.2015

Contents

• Overview of noise emission measurements of light and heavy weapons in Finland

• Induced vibration from heavy weapons

• Background

• Basics

• Measurement results

• Proposed guideline values

• Damage-safe distance

Noise emission measurements

• The noise emission of a significant portion of FDF light and heavy weapons have been measured

• The emission data is used for computational noise assessment of FDF firing ranges

• Measurement conditions affect the uncertainty of the emission data

• Artillery

• 155 K 98 (4)

• 130 K 54 (2)

• 130 TK

• 100 TK

• 122 H 63

• 122 PSH 74 (2)

• Mortars

• 120 KRH (2)

• 81 KRH (2)

• Nemo 120 (5)

• Anti-aircraft

• 23 ITK 61/95

• 12.7 ITKK 96

• standard

• muzzle brake

• Detonations

• 20 kg TNT

• 10 kg TNT

• 5 kg TNT

• 2 kg TNT

• 1 kg TNT

• 200 g TNT

• 60 g TNT

• Artillery grenades

• Mortars

• 100 TK (water impact)

• 112 RSKES APILAS

• 66 KES 88

• 40 KRKK 2005

Weapons measured

• Light infantry weapons

• 8.6 TKIV 2000

• 12.7 RSTKIV 2000

• 7.62 RK 62

• 7.62 RK 95

• live

• blank adapter

• silencer

• 9.00 PIST 80-91

• 7.62 TKIV 85

• M134D-H

• 40 KRKK 2005

• APCs and tanks

• CV9030 main weapon

• BMP-2 main weapon

• Leopard 2A4 main

weapon

• Anti-tank

• 95 S 58-61

• 112 RSKES APILAS

• inert and live

• 66 KES 88

• inert and live

Noise emission factsheets

Measurement conditions

• Good conditions:

• Trial firing range (muzzle blast only)

• Measurement distance: ~100 m for heavy weapons • The distance should be greater

• Large open area

• Hard ground around the weapon

• Reference explosion to assess effects of weather and to estimate the ground correction • Some issues with direct ground correction compensation

• “Other” conditions:

• Measurements of live firing at training grounds

• Measurement distance: long, variable

• Soft ground, non-flat terrain

• Influence of weather

Blast induced vibration - Background

• Finnish Defence Forces (FDF) have received complaints on building damage and annoyance

• Assessment of vibration from heavy weapons and explosions has been under development in Finland

• Pilot project on shooting vibration 2007-09

• Measurements at 3 sites (1 artillery, 2 explosion)

• Literature survey

• Project continued 2009-2014

• Measurements around 5 shooting areas

• Guide (draft) on measurements and assessment

• In-depth investigation of one artillery shooting area

Building vibration

• Impulsive and low-frequency sound waves propagate over long distances, several kilometres

• Building vibration is induced by the passing sound wave

• Figure shows the motion (strongly exaggerated)

a) b)

c) d)

Coupling to structures

Building vibration is induced by airborne sound pressure

= pressure wave = noise

and is coupled to the building structures directly

from the air

Building vibration is not a result of

groundborne vibration

(contrary to underground explosions)

Building response

• Vibration measured in several wooden one-family houses

• The façades are sensitive (right) to heavy weapon sound pressure (left) which has a maximum at low frequencies

60

70

80

90

100

110

1 2 4 8 16 31.5 63 Hz

sound exposure level LpZE, dB

-50

-40

-30

-20

-10

0

2 4 8 16 31.5 63 Hz

velocity response ratio, dB

Damage risk vs. annoyance

• Vibration is strongest on large

and structurally mobile surfaces:

outer walls, roof, intermediate

floors, windows

• Annoyance (vibration and rattle)

is caused by the vibration of these

structures

• Damage risk of foundations is

measured directly from foundations

Shooting vibration (e.g. damage risk of windows)

can and shall also be assessed by measuring

incident noise level outside the house

Valokuvia mittauksista ja taloista!

Assessed parameters

• Noise:

• Measurements of incident sound level outside the building

• Structural damage: unweighted sound exposure level LpZE

• Annoyance: C-weighted sound exposure level LpCE

• LpCE is widely used in Europe and the US for assessing noise annoyance of heavy weapons

• Vibration:

• Structural damage: peak vibration velocity vpeak

• Widely used to assess damage risk from blasting and excavation

• Measured from foundations of buildings

• Annoyance: Wm-weighted vibration velocity exposure level LvWE

• ISO 2631-2 Mechanical vibration and shock – Evaluation of human exposure to whole-body vibration – Vibration in buildings

• Reference level: 50 nm/s

• Adaptation of European guidelines for rail traffic vibration annoyance

Overview of measurement results

• Summary of measurement data 2007-2014: damage risk assessment

Vibration measurement points: Blue: foundation horizontal Red: foundation vertical

Incident sound exposure level LpZE

(outdoors)

0,001

0,01

0,1

1

10

peak v

ibra

tion v

elo

city v

pe

ak, m

m/s

damage risk: 5 mm/s

70

75

80

85

90

95

100

105

110

115

120

125

130

135

140

Sound e

xposure

level, L

pZ

E, dB

damage risk level: 125 dB

Overview of measurement results

• Summary of measurement data 2007-2014: annoyance assessment

70

75

80

85

90

95

100

105

110

115

120

125

130

135

140

Sound e

xposure

level, L

pC

E,

dB

annoyance level:

100 dB

Vibration measurement points: Blue: facade horizontal; Red: 1st floor vertical; Green: 2nd floor vertical

40

45

50

55

60

65

70

75

80

85

90

95

100

105

110

Vib

ration e

xposure

level, L

vW

E, dB

annoyance

level: 76 dB

Incident sound exposure level LpCE

(outdoors)

Measurement result summary

• The damage risk criteria were not exceeded in any of the residential buildings

• The annoyance criteria for noise (and vibration) was exceeded in several residential buildings

• Floor and facade vibration measurement results only represent the measured structures

• The range of structural mobility is large

• Based on our findings, both damage risk and annoyance may be assessed via noise measurements

Proposed guideline values:

damage risk

Proposed guideline values for the assessment of damage risk: Noise: incident sound exposure level outdoors LpZE ≤ 125 dB Vibration: peak vibration velocity, foundations vpeak ≤ 5 mm/s

Proposed guideline values:

annoyance

Proposed guideline values for the assessment of annoyance caused by vibration, rattle and noise: Vibration: Wm-weighted vibration velocity exposure level of floors LvWE ≤ 76 dB Noise + rattle: C-weighted sound exposure level, outdoors, single event LpCE ≤ 100 dB (= FDF noise guideline value) The FDF guideline value for noise assessment :

Noise: Average active day LAeq,r (+10 dB impulse correction) LAeq,r ≤ 55 dB

Damage-safe distance

Artillery, single shot 300 m Artillery, volley (+10 dB) 1 km Distance at which a 130 mm cannon produces LpZE ≈ 125 dB

Determination of distance:

Emission measured obliquely forward (~ 45°) Full +6 dB ground reflection, r2 point-source divergence No barriers, hills, soft ground etc. taken into account Measurement results of emission and immission agreed

well in the example pilot project Impact noise close to muzzle blast (within a few dB) Estimate +10 dB applies to exposure levels, not to peak

• Safety distance of 1 km for artillery

• Circles drawn around residential houses

• An envelope curve drawn inside the circles

• Inside the envelope, shooting noise does not exceed the damage criterion LpZE 125 dB at the houses

Damage-safe

zones