EXHIBIT LIST Reference No: HOC/10001 Petitioner: Phase 2a Teach-ins - PDF document

EXHIBIT LIST Reference No: HOC/10001 Petitioner: Phase 2a Teach-ins Published to Collaboration Area: Friday 23-Mar-2018 Page 1 of 65 No Exhibit Name Page 1 P4 Sound Noise and Vibration Presentation.pdf (P4) 2 - 65 HOC/10001/0001

Sound, Noise and Vibration An explanation Rupert Thornely-Taylor March 2018 P4 (1) HOC/10001/0002

Outline of Presentation What sound is - sources, and ways in which is it transmitted from source to receiver What vibration is - sources, and ways in which is it transmitted from source to receiver Human perception of sound and vibration Measurement scales and indices Assessment approaches - relationship between noise and vibration and human response to them Ways in which noise and vibration and their effects can be reduced Government policy regarding assessment and decision making HS2's application of government policy 2 P4 (2) HOC/10001/0003

Scope of sound and vibration issues SURFACE CONSTRUCTION TUNNEL CONSTRUCTION SURFACE OPERATION - RAILWAY SURFACE OPERATION - FIXED PLANT UNDERGROUND OPERATION 3 P4 (3) HOC/10001/0004

Basics – what sound is Sound is air oscillation that is propagated by wave motion at frequencies between 20 cycles per second (called Hertz, abbreviated Hz) and 20,000 cycles per second (20kHz) 4 P4 (4) HOC/10001/0005

Basics – what sound is Sound decays with distance – It spreads out, is reduced by soft ground surfaces and by intervening obstacles Sound decay is known as attenuation 5 P4 (5) HOC/10001/0006

Basics – what sound is Sound is measured in decibels, abbreviated as dB frequency-weighted to approximate the response of the human ear— in units of dB(A) 6 P4 (6) HOC/10001/0007

Basics – what sound is Noise is unwanted sound The human ear is much more complex than any sound level meter Human beings are more complex still – there is no simple relationship between noise measurements and human response to the noise 7 P4 (7) HOC/10001/0008

Basics – what vibration is Vibration is oscillation of solids that can be propagated through wave motion Vibration in soil decays with distance when it spreads out, and is also attenuated by energy absorption in the soil and by obstacles and discontinuities 8 P4 (8) HOC/10001/0009

Basics – what vibration is Vibration is mainly of interest in the frequency range 0.5Hz to 250Hz and is measured in units of acceleration, velocity or displacement, but it can give rise to audible sound which is then measured in decibels 9 P4 (9) HOC/10001/0010

Basics – what vibration is Like sound, vibration needs to be frequency-weighted to match the response of the human tactile senses 10 P4 (10) HOC/10001/0011

Basics – what vibration is As with sound, human response to vibration is much more complex than can be measured with a meter 11 P4 (11) HOC/10001/0012

Basics - sound Every 10 dB increase is about double the subjective loudness Every 10 dB decrease is about a halving of subjective loudness 12 P4 (12) HOC/10001/0013

Basics - sound A 1 dB change is only perceptible under controlled conditions 13 P4 (13) HOC/10001/0014

Basics - sound A 3 dB change is the minimum perceptible under normal conditions 14 P4 (14) HOC/10001/0015

Basics - sound INDOOR OUTDOOR Noise Level, dB(A) Underneath aircraft landing Rock Band at 1km from runway 110 1m from pneumatic road Night club 100 breaker Food blender at 1m 1m from petrol lawnmower 90 Vacuum cleaner at 1m Pavement of city street 80 Loud voice at 1m Aircraft at height of 200m 70 30m from petrol Normal voice at 1m lawnmower 60 Lorry at 100m, heavy Open plan office rainfall 50 Suburban area at night, no Refrigerator at 1m 40 local traffic Concert hall background Country area at night, no noise local traffic 30 Very remote rural area no Extremely quiet room wind 20 Wilderness at night with no Nearly Silent 10 wind Threshold of audibility Threshold of audibility 0 15 P4 (15) HOC/10001/0016

Basics - sound Sounds in the environment normally vary in level, for example due to the passage of vehicles, or trains. The sound level therefore varies with time, showing highs and lows. The highs are measured with an index called L Amax L Amax levels are presented in the tables in Volume 5 of the Environmental Statement. These are L AFmax levels where F is the “fast” time weighting (0.125 second) 16 P4 (16) HOC/10001/0017

Basics - sound Because many noise events are more annoying than a few noise events, an index is needed to take account of both level and number (and duration) of events Sounds that vary in level are therefore measured in equivalent continuous sound level , used internationally L eq,T (or L Aeq,T ) T = time period L Aeq,T levels are presented both in the tables in Volume 5 of the Environmental Statement and also plotted as contours for the time periods (0700-2300) and (2300-0700) 17 P4 (17) HOC/10001/0018

Basics - sound L Aeq is not an average of sound levels. It is an index that is an average of the energy content of sound levels. A sound which is twice as loud as another contains ten times the amount of energy. So averaging the energy gives a result dominated by the highest sounds in the averaging process. e.g. five events of equal duration measuring 50 dB together with one of 70 dB gives an ordinary arithmetic average of 53 dB — but the L Aeq value is 62 dB 18 P4 (18) HOC/10001/0019

L Aeq is no ordinary average… Decibel scale 70 L ASmax 60 decibels 50 40 30 0 50 100 150 200 250 300 350 400 time, seconds 19 P4 (19) HOC/10001/0020

L Aeq is no ordinary average… Logarithmic energy scale 10000000 1000000 energy 100000 10000 1000 0 50 100 150 200 250 300 350 400 time, seconds 20 P4 (20) HOC/10001/0021

L Aeq is no ordinary average… Linear energy scale 8000000 7000000 6000000 5000000 energy 4000000 3000000 2000000 1000000 0 0 50 100 150 200 250 300 350 400 time, seconds 21 P4 (21) HOC/10001/0022

L Aeq is no ordinary average… 70 60 L Aeq decibels 50 40 AVERAGE LEVEL 30 0 50 100 150 200 250 300 350 400 time, seconds 22 P4 (22) HOC/10001/0023

Basics - sound With L Aeq : doubling the energy in the sound, doubling the number of sources, doubling the duration of a sound event, doubling the number of similar events each give +3dB 23 P4 (23) HOC/10001/0024

Basics - sound With L Aeq : ten times the energy in the sound, ten times the number of sources, ten times the duration of a sound event, ten times the number of similar events each give +10dB 24 P4 (24) HOC/10001/0025

Basics - sound Environmental Indices based on L Aeq Noise in the day, evening and night periods has different effects, and for purposes such as noise mapping this is taken into account by calculating L Aeq separately for the three periods as annual energy - average outdoor noise levels: L day 0700-1900 L evening 1900-2300 L night 2300-0700 and combining these into one 24-hour long term index 25 P4 (25) HOC/10001/0026

Basics - sound Day-Evening-Night Level L den Allowance is made for greater noise sensitivity at night, and to a lesser extent in the evening. Night noise is treated as if it were 10 dB higher than the physical level Evening noise is treated as if it were 5 dB higher than the physical level. 26 P4 (26) HOC/10001/0027

Basics - sound Day-Evening-Night Level L den L day is then combined with L evening +5dB and L night +10 dB to calculate L den The difference between L den and L Aeq(0700-2300) depends on the relative amounts of day, evening and night noise. For HS2 L den is less than 1 dB greater in numerical level than L Aeq , so for practical purposes, L Aeq levels can be read as L den levels 27 P4 (27) HOC/10001/0028

Basics – sound and vibration In terms of human response at environmental sound levels: • Sound levels on their own mean nothing. • Social surveys link sound levels with human response • There is always a wide distribution of responses • There is never a clear distinction between “acceptable” and “unacceptable” or “significant” and “not significant” The same is true of vibration 28 P4 (28) HOC/10001/0029

Basics - sound 29 P4 (29) HOC/10001/0030

Basics - sound 30 P4 (30) HOC/10001/0031

Basics - sound 31 P4 (31) HOC/10001/0032

Basics - sound Noise from fixed plant is assessed by comparing the L Aeq with a penalty added unless the noise is characterless against the background noise in L A90 . L A90 measures quiet moments e.g. between passing vehicles or aircraft. 32 P4 (32) HOC/10001/0033

Basics - sound 50 decibels 40 L A90 30 0 50 100 150 200 250 300 350 400 time, seconds 33 P4 (33) HOC/10001/0034

Basics – vibration (affecting people) Vibration felt by the sense of touch is assessed using Vibration Dose Value (VDV) 34 P4 (34) HOC/10001/0035

Basics – vibration (affecting buildings) Vibration affecting buildings is assessed using peak vibration velocity called “Peak Particle Velocity” or PPV. 35 P4 (35) HOC/10001/0036

Basics – vibration (heard as noise) Groundborne noise is assessed using maximum sound level, L Amax,S where S is the “slow” time weighting (1 second) 36 P4 (36) HOC/10001/0037