hs kan march 2007
DESCRIPTION
CIVL 395 Environmental Impact Assessment [4] Housing Development in Tuen Mun Area 1 Proposed Bridge at Tuen Mun Area 18. HS Kan March 2007. Air Impact Assessment – CALINE4. www.dot.ca.gov/hq/env/air/index.htm. Noise Impact Assessment. Noise measurement – A-weighting for human perception. - PowerPoint PPT PresentationTRANSCRIPT
CIVL 395 Environmental Impact Assessment [4]
Housing Development in Tuen Mun Area 1Proposed Bridge at Tuen Mun Area 18
HS Kan
March 2007
Air Impact Assessment – CALINE4
www.dot.ca.gov/hq/env/air/index.htm
Noise Impact Assessment
Noise measurement – A-weighting for human perception
Facade Noise Levels from Road Traffic(Extracted from
The Hong Kong Planning Standards & Guidelines, Planning Department)
Peak hourtraffic flow
(veh/h)
Facade noise levels L10(1h),
dB(A) -Vehicular
speed (30 kph)
Facade noise levels L10(1h),
dB(A) -Vehicular
speed (50 kph)
Facade noise levels L10(1h),
dB(A) -Vehicular
speed (70 kph)
Facade noise levels L10(1h),
dB(A) -Vehicular
speed (85 kph)
Facade noise levels L10(1h),
dB(A) -Vehicular
speed (100kph)
250 70 71 72 73 74
500 73 74 75 76 77
1000 76 77 78 79 80
2000 79 80 81 82 83
3000 80 81 82 83 84
5000 83 84 85 86 87
10000 86 87 88 89 90
Noise Impact Assessment Legislation, standards and criteria
Noise Control Ordinance Technical Memorandum on Noise from Places other than Domestic Premises, Public Places or Co
nstruction Sites Technical Memorandum on Noise from Construction Work other than Percussive Piling
http://www.epd.gov.hk/epd/english/environmentinhk/noise/guide_ref/tm_nonpp.html Technical Memorandum on Noise from Percussive Piling
Noise sensitive receivers All domestic premises, hotel, hospital, educational institution, place of public worship, library, co
urt, arts performance facilities, etc Area Sensitivity Ratings ASR
Urban / rural / low-density residential Table 1 in the Technical Memorandum
Influencing factors IF (on the ASR) Presence of industrial areas, major roads, etc
Basic noise levels BNL Table 2 in the Technical Memorandum
Sound levels for Powered Mechanical Equipment PME Table 3 in the Technical Memorandum For summation of different sources, Table 4 in the Technical Memorandum
Acceptable noise levels ANL For this exercise, you may take the ANL as being directly equal to the BNL
Distance attenuation Distance attenuation in dB(A) = 20 log D + 8, where D = distance in m Table 5 in the Technical Memorandum
Outline Zoning Plan of the Bridge Site
Source:
The Planning Department website
Government / Institution / Community
Green Belt
Open Space
Residential (Group A)
Proposed Bridge at Tuen Mun Area 18
(1) During
foundation works: bored piling machine, air compressor, excavator, steel bender, etc;
(2) During pile construction: concrete truck mixer, concrete pump, vibratory poker, etc.
(3) etc.
Consider mainly the noise impact from powered mechanical equipment at the southern abutment at various stages, e.g.
Table 1 - Area Sensitivity Ratings (ASRs)
Type of Area Containing NSR Degree to which NSR is affected by IF
Not Affected Indirectly Affected
Directly Affected
Rural area, including country parks or village type developments
A B B
Low density residential area consisting of low-rise or isolated high-rise developments
A B C
Urban area B C C
Area other than those above
B B C
Basic Noise Levels (BNLs)
Time Period ASR
A B C
All days during the evening (1900 to 2300 hours), and general holidays (including Sundays) during the day-time and evening (0700 to 2300 hours)
60 65 70
All days during the night-time (2300 to 0700 hours)
45 50 55
Table 2 of the Technical Memorandum
Table 4 - Summation of Noise Levels
Difference in dB(A) between two noise levels being summed
Amount in dB(A) to add to the higher noise level
0 to 0.5 3.0
1.0 to 1.5 2.5
2.0 to 3.0 2.0
3.5 to 4.5 1.5
5.0 to 7.0 1.0
7.5 to 12.0 0.5
more than 12.0 0
Control of Noise Impact
The Source Elimination, Reduction, Shielding, Absorption
The Transmission Breaking, Weakening
The Receiver Shielding, Protection, Removal
Source ReceiverTransmission
Noise Impact Assessment
Control and mitigation Construction
Choice of construction method Use of silenced powered mechanical equipment Proper equipment maintenance Proper location and orientation of equipment Noise screens Good site practices
Operation Reduction Containment Shielding Protecting the receiver
Cantilever Barrier at West Kowloon Expressway
Enclosure barrier at Wong Chu Road, Tuen Mun