Noise emission and induced vibration from heavy .Noise emission and induced vibration from heavy

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  • 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 faades 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