5 Ground-borne Noise Impact

5.2 Environmental Legislation, Plans, Standards, and Guidelines

5.2.1 Construction ground-borne noise is under the control of the Noise Control Ordinance (NCO), the Environmental Impact Assessment Ordinance (EIAO), and their subsidiary Technical Memorandum.

5.2.2 Noise arising from the general construction works of the Project during normal daytime hours (0700-1900 except general holidays and Sunday) is governed by the EIAO-TM. With reference to the Technical Memorandum for the Assessment of Noise from Places Other Than Domestic Premises, Public Places or Construction Sites (IND-TM) under the NCO, the criteria for noise transmitted primarily through the structural elements of the building or buildings are expected to be 10dB(A) less than the relevant acceptable noise level (ANL). These criteria apply to all residential buildings, schools, clinics, hospitals, temples and churches.

5.2.3 During the restricted hours (i.e. between 1900 and 0700 on a normal working day or at any time on a general holiday and Sunday), the construction noise is controlled by the Technical Memorandum on Noise from Construction Work other than Percussive Piling (GW-TM). Similarly, the ground-borne noise criteria is limited to 10dB(A) below the respective ANL. A Construction Noise Permit (CNP) is required for construction activities involving the use of Power Mechanical Equipment (PME) carried out in restricted hours.

5.2.4 The construction ground-borne noise criteria for the identified ground-borne noise sensitive receivers (GBNSRs) are tabulated in Table 5.1 below.

Table 5.1 Construction Ground-borne Noise Criteria

Type of GBNSR / Assessment Point ⁽¹⁾	Construction Ground-borne Noise Criteria
Type of GBNSR / Assessment Point ⁽¹⁾	Daytime (0700-1900 hrs) (except General Holidays & Sunday) (L_{eq, 30min}, dB(A))	Daytime during general holidays and Sundays and all days during Evening⁽²⁾ (1900 to 2300 hrs) (L_{eq, 5min}, dB(A))	Night⁽²⁾ (2300 to 0700 hrs) (L_{eq, 5min}, dB(A))
Domestic premises, hotels and hostels	65	60 for ASR “C”/ 55 for ASR “B” / 50 for ASR “A”	45 for ASR “C” / 40 for ASR “B” / 35 for ASR “A”
Churches, Educational Institutions and Clinics	60 / 55 ⁽³⁾	60 for ASR “C”/ 55 for ASR “B” / 50 for ASR “A”	- ⁽⁴⁾

Notes:

(1) Assessment point locates at an internal location of a building in which the GBNSR is located.

(2) Ground-borne noise is deemed not to be affected by Influencing Factors (IF), therefore, the effect of IF should not be considered to determine the appropriate noise criteria during restricted hours.

(3) A 5dB(A) reduction to the ground-borne noise criteria is recommended for school during examination period.

(4) No sensitive use/activity during this period.

5.2.5 There are no statutory procedures and criteria under the NCO and EIAO for assessing blasting noise impacts. The administrative and procedural control of all blasting operations in Hong Kong is vested in the Mines Division of the Civil Engineering and Development Department (CEDD). The Dangerous Goods (General) Regulation (Cap. 295) also stipulates that no person shall carry out blasting unless he possesses a valid mine blasting certificate to be issued by the Mines Division of CEDD. The Superintendent of Mines will review the application on a case-by-case basis before issuing the Mine Blasting Certificate.

Operational Phase

5.2.6 With reference to the IND-TM, the criteria for noise transmitted primarily through the structural elements of the building or buildings is 10dB(A) less than the relevant acceptable ANL. The same criteria are applied to all residential buildings, schools, clinics, hospitals, temples and churches. The criteria applied for assessment of ground-borne noise are summarized in Table 5.2 below.

Table 5.2 Operational Ground-borne Noise Criteria

Type of GBNSR / Assessment Point ⁽¹⁾	Ground-borne Noise Criteria, (L_{eq, 30min}, dB(A))
Type of GBNSR / Assessment Point ⁽¹⁾	Day and Evening⁽²⁾ (0700-2300 hrs)	Night⁽²⁾ (2300 to 0700 hrs)
Domestic premises, hotels and hostels	60 for ASR “C”/ 55 for ASR “B”/ 50 for ASR “A”	50 for ASR “C”/ 45 for ASR “B”/ 40 for ASR “A”
Churches, Educational Institutions and Clinics	60 for ASR “C”/ 55 for ASR “B”/ 50 for ASR “A”	- ⁽³⁾

Notes:

(1) Assessment point locates at an internal location of a building in which the GBNSR is located.

(2) Ground-borne noise is deemed not to be affected by IF, therefore, the effect of IF should not be considered to determine the appropriate noise criteria.

(3) No sensitive use/activity during this period.

5.3 Description of the Environment

5.3.1 The Project is located in the northern part of the New Territories where majority of the area is predominantly in rural nature. The underground alignment would pass through a large area of wetlands, agricultural lands, private lots, brown field sites, village developments and low-density residential developments. There are also numerous planned housing development located within and in the vicinity of the assessment area such as public housing developments at Kam Tin South, public housing development near Sha Po Tsuen, as well as the new development areas at Kwu Tung, San Tin and Ngau Tam Mei.

5.3.2 The existing noise climate is dominated by the road traffic noise from Tsing Long Highway, San Tin Highway and Fanling Highway, as well as the railway noise from Tuen Ma Line (TML) at Kam Tin area are identified as dominant noise sources at the Project area. In addition to road traffic noise, isolated industrial operations scattered throughout the Project area also contribute to the overall ambient noise levels. These operations include open storage facilities, warehouse, container back-up areas and car stripping/repair workshops.

5.4 Sources of Impact

Construction Phase

5.4.1 Potential ground-borne noise impact during construction phase would arise mainly from Tunnel Boring Machine (TBM) operation and PME to be used for rock breaking/drilling including breakers and drill rigs during tunnelling works. The construction of the Project will tentatively commence in 2025 for completion in 2034. The plant inventory (Appendix 4.6 refers) was provided and confirmed by the construction professionals for the ground-borne construction noise impact assessment. It is anticipated that there would be only a representative construction phasing (i.e. along the mainline tunnels/adits) during the construction of tunnels and adits that would induce ground-borne noise impact to the GBNSRs. Detailed construction programme is presented in Appendix 2.2.

5.4.2 Based on the best available information at the time of preparation of this EIA report, potential cumulative construction ground-borne noise from concurrent projects is not anticipated.

Operational Phase

5.4.3 When trains operate in tunnels that are located in close proximity to occupied structures, there is a possibility that vibrations associated with train passbys can be transmitted through the ground and structure and be radiated as noise in the occupied spaces within the structure. The transmitted noise through structures may have potential impact on the GBNSRs.

5.4.4 Cumulative ground-borne railway noise impact from the Project, HSR at Ngau Tam Mei, and LMCSL at Kwu Tung would be expected and therefore was considered in the assessment.

5.5 Ground-borne Noise Sensitive Receivers

5.5.1 The assessment area for the noise impact assessment was set as 300m from the boundary of the Project and the works areas/works sites. Site visits were conducted for NSRs identification. With reference to the criteria set out in Annex 13 of EIAO-TM, observations from site visits and review of relevant land use plans including the Outline Zoning Plans (OZP), Development Permission Area Plans, Outline Development Plans, Layout Plans and other relevant published land use plans, including plans and drawings published by the Lands Department and any land use and development applications approved by the Town Planning Board, representative existing and planned GBNSRs, within 300m assessment area of the Project boundary were identified. All GBNSRs in the assessment area are shown in Figure Nos. C1603/C/NOL/ACM/M52/310 - 323 and Figure Nos. C1603/C/NOL/ACM/M52/330 - 339. Photographs of representative NSRs are shown in Appendix 4.4.

5.5.2 Representative GBNSRs located closest to the tunnel alignment are considered the most affected locations. A summary of representative GBNSRs, including planned and existing GBNSRs, for different noise impact assessments is presented in Table 5.3 and Table 5.4 with their locations shown in Figure Nos. C1603/C/NOL/ACM/M52/500 - 511.

Table 5.3 Representative Existing Ground-borne Noise Sensitive Receivers during Construction and Operational Phases

GBNSR ID	Description	Land Use⁽¹⁾	No. of Storey	Type of Area	Influencing Factor	Degree to which GBNSR is affected ⁽²⁾	ASR⁽²⁾	Construction GBN Impact		Operation GBN Impact
GBNSR ID	Description	Land Use⁽¹⁾	No. of Storey	Type of Area	Influencing Factor	Degree to which GBNSR is affected ⁽²⁾	ASR⁽²⁾	TBM⁽¹⁰⁾	PME	Operation GBN Impact
KSR-G01	No.110 Cheung Chun San Tsuen	R	2	Low density residential area	-	-	A	√		√
KSR-G02	Blk 77, Sam Yuen	R	3	Low density residential area	-	-	A	√		√
KSR-G03	Kam Tin Mung Yeung Public School	E	2	Low density residential area	-	-	A	√		√
KSR-G04	No.297-298 Kut Hing Wai	R	3	Low density residential area	-	-	A	√		√
KSR-G05	Kat Hing Garden	R	3	Low density residential area	-	-	A	√		√
AUT-G01	No. 173, Mo Fan Heung	R	1	Area other than those above⁽³⁾	Industrial Zone	Within 100m of Industrial Zone⁽⁹⁾	B	√		√
AUT-G02	No. 137, Mo Fan Heung	R	1	Area other than those above⁽³⁾	Industrial Zone	Within 100m of Industrial Zone⁽⁹⁾	B	√		√
AUT-G03	No. 80, Mo Fan Heung	R	1	Area other than those above⁽³⁾	Industrial Zone	Within 100m of Industrial Zone⁽⁹⁾	B	√		√
AUT-G06	Tower 2B, Park Yoho Silica	R	14	Area other than those above ⁽⁴⁾	-	-	B	√		√
AUT-G07	Tower 9B, Park Vista	R	16	Area other than those above ⁽⁴⁾	-	-	B	√		√
AUT-G08	Tower 8B, Park Yoho	R	14	Area other than those above ⁽⁴⁾	-	-	B	√		√
AUT-G09	In Keen Garden Phase 1	R	3	Area other than those above ⁽⁴⁾	-	-	B	√		√
AUT-G10	York International Kindergarten ⁽⁸⁾	E	1	Area other than those above ⁽⁴⁾	-	-	B	√		√
AUT-G11	169 Pok Wai	R	2	Low density residential area	San Tin Highway	Indirectly Affected	B	⁽¹¹⁾	√
NTM-G01	The Vineyard	R	3	Low density residential area	-	-	A	√		√
NTM-G02	China Bible Seminary	E	3	Low density residential area	-	-	A	√		√
NTM-G03	House A, Greenacres Villa	R	3	Low density residential area	-	-	A	√		√
NTM-G04	Hongtai Home for the Aged Limited	EC	3	Area other than those above ⁽⁵⁾	-	-	B	√		√
NTM-G04a	Temporary Structure near Ching Yau Road	R	1	Area other than those above ⁽⁵⁾	-	-	B	√		√
NTM-G06	Village House near Fuk Hing Lei	R	2	Low density residential area	-	-	A	√		√
NTM-G07	Village House near Wang Ping Shan South Road	R	3	Area other than those above ⁽⁶⁾	-	-	B	√	√	√
NTM-G08	Village House near Wang Ping Shan South Road	R	1	Area other than those above ⁽⁶⁾	-	-	B	√	√	√
NTM-G09	Village House in Long Ha	R	1	Low density residential area	-	-	A	⁽¹¹⁾	√
SAT-G03	Temporary Structure near Shek Wu Wai	R	2	Low density residential area	-	-	A	√
KTU-G01	Village House in Chau Tau Tsuen	R	2	Low density residential area	Fanling Highway	Not Affected	A	√		√
KTU-G02	Village House in Chau Tau Tsuen	R	1	Area other than those above ⁽⁷⁾	Fanling Highway	Not Affected	B	√		√

Notes:

(1) R – Residential; EC – Elderly Centre; E – Educational institutions.

(2) Ground-borne noise is deemed not to be affected by IF, therefore, the effect of IF should not be considered to determine the appropriate noise criteria.

(3) GBNSR AUT G01 to G03 are located in low density development with industrial zone which numerous open storages/industrial uses are located in the vicinity of the GBNSRs, therefore, type of area was considered to be “Area other than those above”.

(4) GBNSR AUT G06 to G10 are located in a medium to high-density residential area with some scattered industrial activities (e.g. garage), therefore, type of area was considered to be “Area other than those above”.

(5) According to Section 16 of LC Paper No. CB(1)756/20-21(01) - Using Brownfield Clusters for Public Housing Development (Second Phase Review) and Other Developments, Ngau Tam Mei Area would be developed to provide a mix of over 6,000 public and private housing units. Based on this information, type of area was considered to be “Area other than those above”.

(6) In view of open storages/industrial uses (e.g. Jaguar Cool Chain Co Ltd. And Wing Ming Farm) located in the vicinity of the GBNSRs, type of area was considered to be “Area other than those above”.

(7) In view of open storages/industrial uses located in the vicinity of the GBNSRs, type of area was considered to be “Area other than those above”.

(8) No examination would be anticipated at kindergarten.

(9) Considering the existing industrial zone would be changed to other land uses for Sha Po Public Housing Development, for conservative approach, the effect of industrial zone was not considered to determine the appropriate noise criteria.

(10) The locations of TBM operation are indicated in Figure No. C1603/C/NOL/ACM/M50/305.

(11) This NAP is located at more than 100m from TBM tunnels. Other representative GBNSRs, which are located closer to the TBM Tunnel, were considered, and thus this NAP was not selected for prediction.

Table 5.4 Representative Planned Ground-borne Noise Sensitive Receivers during Construction and Operational Phases

GBNSR ID	Description	Land Use⁽¹⁾	No. of Storey	Type of Area	Influencing Factor	Degree to which GBNSR is affected ⁽²⁾	ASR⁽²⁾	Construction GBN Impact		Operation GBN Impact
GBNSR ID	Description	Land Use⁽¹⁾	No. of Storey	Type of Area	Influencing Factor	Degree to which GBNSR is affected ⁽²⁾	ASR⁽²⁾	TBM⁽¹⁴⁾	PME	Operation GBN Impact
KSR-PG01a	Planned School in Park Yoho Phase 3	E	-⁽³⁾	Area other than those above⁽⁴⁾	-	-	B	√		√
KSR-PG01b	Proposed Residential Development in Park Yoho Phase 3	R	-⁽³⁾	Area other than those above⁽⁴⁾	-	-	B	√		√
KSR-PG01c	Proposed Residential Development Park Yoho Phase 2	R	-⁽³⁾	Area other than those above⁽⁴⁾	-	-	B	√		√
KSR-PG01d	Planned School in Park Yoho Phase 3	E	-⁽³⁾	Area other than those above⁽⁴⁾	-	-	B	√		√
KSR-PG02	Kam Tai Road Residential Development	R	-⁽³⁾	Low density residential area ⁽⁵⁾	-	-	A	√		√
KSR-PG03	Grand Mayfair (under Construction)	R	16	Area other than those above⁽⁶⁾	-	-	B			√
KSR-PG04	Future Kam Sheung Road Package 2 Property Development	R	-⁽³⁾	Area other than those above⁽⁷⁾	-	-	B			√
KSR-PG05a	Planned G/IC Site at Kam Tin South Housing Development	G/IC	-⁽³⁾	Area other than those above⁽⁸⁾	-	-	B			√
KSR-PG05b	Planned Residential Block at Kam Tin South Housing Development	R	-⁽³⁾	Area other than those above⁽⁸⁾	-	-	B			√
KSR-PG06a	Planned G/IC Site at Kam Tin South Housing Development	G/IC	-⁽³⁾	Area other than those above⁽⁸⁾	-	-	B			√
KSR-PG06b	Planned School Site at Kam Tin South Housing Development	E	-⁽³⁾	Area other than those above⁽⁸⁾	-	-	B			√
KSR-PG06c	Planned Residential Block at Kam Tin South Housing Development	R	-⁽³⁾	Area other than those above⁽⁸⁾	-	-	B			√
AUT-PG01	Planned Residential Block at Sha Po Public Housing Development	R	-⁽³⁾	Area other than those above⁽⁹⁾	-	-	B	√		√
AUT-PG03	Planned Residential Block at Sha Po Public Housing Development	R	-⁽³⁾	Area other than those above⁽⁹⁾	-	-	B	√		√
NTM-PG01	Potential Development at Land Use Review Study for Ngau Tam Mei Area (NTM LUR)	-⁽³⁾	-⁽³⁾	Area other than those above⁽¹⁰⁾	-	-	B			√
SAT-PG01a	Potential Housing Development in San Tin / Lok Ma Chau Development Node (STLMC DN)	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01b	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01c	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01d	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01e	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01f	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01g	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01h	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01i	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01j	Potential Housing Development in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG01k	Potential Cultural & Recreational Complex in STLMC DN	G/IC	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG02	Potential Cultural & Recreational Complex in STLMC DN	G/IC	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG02a	Potential GIC Facility in STLMC DN	G/IC	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG03a	Potential School in STLMC DN	E	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG03b	Potential School in STLMC DN	E	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG03c	Potential GIC Facility in STLMC DN	G/IC	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
SAT-PG03d	Potential FSD Staff Quarter in STLMC DN	R	-⁽³⁾	Area other than those above⁽¹¹⁾	-	-	B			√
KTU-PG01	Planned Housing Development at Kwu Tung North NDA	R	-⁽³⁾	Area other than those above⁽¹²⁾	-	-	B	√		√
KTU-PG01a	Planned Housing Development at Kwu Tung North NDA	R	-⁽³⁾	Area other than those above⁽¹²⁾	-	-	B	√		√
KTU-PG02	Planned Housing Development at Kwu Tung North NDA	R	-⁽³⁾	Area other than those above⁽¹²⁾	-	-	B			√
KTU-PG02a	Planned Housing Development at Kwu Tung North NDA	R	-⁽³⁾	Area other than those above⁽¹²⁾	-	-	B			√
KTU-PG03	Planned Housing Development at Kwu Tung North NDA	R	-⁽³⁾	Area other than those above⁽¹²⁾	-	-	B			√
KTU-PG03a	Planned Housing Development at Kwu Tung North NDA	R	-⁽³⁾	Area other than those above⁽¹²⁾	-	-	B			√

Notes:

(1) R – Residential; EC – Elderly Centre; E – Educational institutions; G/IC – Government, Institution or Community.

(2) Ground-borne noise is deemed not to be affected by IF, therefore, the effect of IF should not be considered to determine the appropriate noise criteria.

(3) Information subject to the design of planned development.

(4) According to planning application A/YL-KTN/604 and A/YL-KTN/663, Park Yoho Phase 2 and 3 will be developed to a medium to high-density residential area, therefore, type of area was considered to be “Area other than those above”.

(5) According to planning application No. A/YL-KTN/791, the Kam Tai Road Residential Development will be developed to residential area with low-rise and isolated high-rise development, therefore, type of area was considered to be “Low density residential area”.

(6) According to the information in Sales Brochure of the development, Grand Mayfair I will be developed to a medium to high-density residential area, therefore, type of area was considered to be “Area other than those above”.

(7) As the areas in the vicinity of the Future Kam Sheung Road Package 2 Property Development (i.e. Grand Mayfair and Kam Tin South Public Housing Development) will be developed to medium to high-density residential area, type of area was considered to be “Area other than those above”.

(8) According to the building layout plans provided by Housing Department, the Planned Kam Tin South Development (Site 1 & 6) would be developed to medium to high-density residential area, therefore, type of area was considered to be “Area other than those above”. For KSR-PG06a, the proposed facilities inside the GIC site would refer to the District Council Discussion Papers (No. 15/2023) on 25 April 2023 for Yuen Long District Council. (https://www.districtcouncils.gov.hk/yl/doc/2020_2023/en/dc_meetings_doc/23824/dc_paper_no_2023_15.pdf)

(9) According to the block layout provided by Housing Department, the Proposed Public Housing Development Near Sha Po Tsuen would be developed to medium to high-density residential area, type of area was therefore considered to be “Area other than those above”.

(10) According to Section 16 of LC Paper No. CB(1)756/20-21(01) - Using Brownfield Clusters for Public Housing Development (Second Phase Review) and Other Developments, Ngau Tam Mei Area would be developed to provide a mix of over 6,000 public and private housing units. Based on this information, type of area was considered to be “Area other than those above”.

(11) According to Section 14 of LC Paper No. CB(1)756/20-21(01) - Using Brownfield Clusters for Public Housing Development (Second Phase Review) and Other Developments, the San Tin Lok Ma Chau Development Node (STLMC DN) would be developed as a new development area supporting an estimated housing yield of 31 000 units together with economic and community facilities. Based on this information, type of area was considered to be “Area other than those above”.

(12) Based on the information provided in the approved NENT NDA EIA report (Register No.: AEIAR-175/2013), the area near KTU Station will be developed to a medium to high-density residential area, type of area was therefore considered to be “Area other than those above”.

(13) The identification of GBNSRs was based on the following sources of best available information:

§ KSR-PG01a, 1b, 1c & 1d - Reference was made to planning application A/YL-KTN/604 and A/YL-KTN/663, and the GBNSRs were identified based on the Indicative Master Layout Plan shown in these planning applications.

§ KSR-PG02 - According to the master layout plan shown in the Planning application No. A/YL-KTN/791, a setback distance of 50m from the existing TML was adopted for all GBNSRs. Therefore, the identified GBNSR was assumed to be located at 50m from the existing TML.

§ KSR-PG03 – Reference was made to the building layout provided in Sales Brochure of the development (See Note 6).

§ KSR-PG04 – No indicative layout plan was available during the course of EIA study and therefore the indicative location of GBNSR was set at the boundary of the Future Kam Sheung Road Package 2 Property Development.

§ KSR-PG 05b & 06c - Reference was made to the tentative building layout plans provided by Housing Department.

§ KSR-PG05a & 06b – No indicative layout plan was available during the course of EIA study and therefore the indicative location of GBNSR was set at the boundary of the G/IC site.

§ KSR-PG06a - Based on the best available information provided by CLP Power Hong Kong Limited, there will be a cable reserve zone along the southwest boundary of the G/IC site and a planned substation to be located at southern part of the GI/C site. The NAP was assumed at a location outside the cable reserve zone and the planned substation.

§ AUT-PG01 & 03 - Reference was made to the building layout plans in Final Report (Sha Po) of Agreement No. CE 10/2020 (CE) Site Formation and Infrastructure Works for Proposed Public Housing Developments at Sha Po, Shap Pat Heung and Tai Kei Leng, Yuen Long – Feasibility Study, as provided by Housing Department.

§ NTM-PG01 - Reference was made to the draft Preliminary Outline Development Plan (PODP) of Land Use Review Study for Ngau Tam Mei Area provided by the relevant government department.

§ SAT-PG01a to 1k, 02, 02a, 03a to 03d - Reference was made to the Recommended Outline Development Plan (RODP) provided by the project proponent of STLMC DN.

§ KTU-PG01, 01a, 02, 02a, 03 & 03a - Reference was made to the information provided by CEDD.

(14) The locations of TBM operation are indicated in Figure No. C1603/C/NOL/ACM/M50/305.

5.6 Assessment Methodologies

Construction Phase

5.6.1 The methodology used to determine ground-borne noise levels during the construction phase is based on the method recommended by the U.S. Department of Transportation and Federal Transit Administration. This projection methodology was also adopted in the approved EIA reports for Shatin to Central Link - Tai Wai to Hung Hom Section (Register No.: AEIAR-167/2012), Shatin to Central Link - Hung Hom to Admiralty Section (Register No.: AEIAR-166/2012) and Improvement of Lion Rock Tunnel (Register. No.: AEIAR-242/2022).

5.6.2 The main components of the proposed construction ground-borne noise assessment methodology are:

· Vibration source levels from the operation of TBM and concerned PMEs (e.g. hydraulic breaker and rock drill);

· Vibration propagation through the ground to the structure foundation;

· Vibration reduction due to the soil/structure interface;

· Vibration propagation through the building and into occupied areas; and

· Conversion from floor and wall vibration to noise.

5.6.3 The vibration level L_v,rmsat a distance R from the source is related to the vibration source level at a reference distance R₀. The conversion from vibration levels to ground-borne noise levels was determined by the following factors:

C_dist: Distance attenuation

C_damping: Soil damping loss across the geological media

C_building: Coupling loss into building foundation

C_floor: Coupling loss per floor

C_noise: Conversion factor from floor vibration levels to noise levels

C_multi: Noise level increase due to multiple sources

C_cum: Cumulative effect due to neighbouring sites

5.6.4 The ground-borne noise level (L_p) inside the GBNSR was predicted using the following equation:

L_p = L_v,rms + C_dist + C_damping + C_building + C_floor + C_noise + C_multi+ C_cum

5.6.5 The assessment was based on worst-case assumptions with the details of the assumptions described in the following sections.

Reference Vibration Sources

5.6.6 For the assessment of ground-borne noise due to hydraulic breaker, rock drill and TBM, reference was made to the assessment approach, source terms and transmission factors adopted in the approved EIA studies for Kowloon Southern Link (KSL) and Shatin to Central Link (SCL) projects. The reference source levels adopted for assessment are given in Table 5.5.

Table 5.5 Reference Source Levels

Plant	Reference Vibration Level, mm/s	Remarks
Hydraulic Breaker	0.298	rms Vibration velocity level at reference distance of 5.5m
Rock Drill	0.536	rms Vibration velocity level at reference distance of 5.5m
TBM	2.5 ⁽¹⁾	PPV Vibration velocity level at reference distance of 5.5m

Note:

(1) The vibration in-situ measurements for the TBM operation were conducted during the bored tunnelling of Kwai Tsing Tunnel under West Rail project, and the measurement data was adopted in the approved KSL EIA report (Register No.: AEIAR-083/2005) for ground-borne noise assessment. Same TBM had subsequently been used for the construction of LMCSL. In addition, the vibration measurements taken for Kwai Tsing tunnelling works were conducted at a geology which consists of mainly granite, which would be expected to generate higher vibration. As presented in Appendix 2.1, the geology along the NOL alignment comprises mainly softer material (e.g. decomposed tuff), except a section near KSR Station (chainage approx. 1+350 to 2+230) which consists of granite. As confirmed by the MTR, the TBMs to be adopted for the construction of NOL tunnels would be similar to that was used for LMCSL. As such, the vibration measurement data was therefore considered to be applicable for the purpose of assessing TBM ground-borne noise, and no adjustment to the source term would be required.

Distance Attenuation (C_dist)

5.6.7 Ground-borne noise can be attenuated by longer distance of vibration energy transmission pathway. The following equation was used to evaluate the distance attenuation factor (C_dist):

C_dist= 20 x log (R/R₀), where

where

R separation between the tunnel boundary and the GBNSR

R₀ reference distance of the vibration measurement (i.e. 5.5m)

Soil Damping (C_damping)

5.6.8 No damping attenuation was adopted in this assessment as conservative approach.

Coupling Loss into Building Foundation, (C_building)

5.6.9 The coupling loss into building structures represents the change in the incident ground-surface vibration due to the presence of the piled building foundation. The correction factor was assumed to be zero in this assessment as conservative approach.

Coupling Loss per Floor (C_floor)

5.6.10 The coupling loss per floor represents the floor-to-floor vibration transmission attenuation. For multi-storey buildings, a common value for the attenuation of vibration from floor-to-floor is approximately 1 dB attenuation in the upper floor regions and greater than 3 dB attenuation at lower floors. Coupling loss of 1 dB reduction per floor was assumed in this assessment for a conservative approach.

Conversion from Floor Vibration to Noise Levels (C_noise)

5.6.11 A -27dB correction was assumed for conversion of vibration to noise (re. 20μPa) for residential units and school and this is in line with the previous approved EIA report.

Noise Level Increase due to Multiple Sources (C_multi)

5.6.12 This represents the increase in noise level due to multiple noise sources. For TBM operation, uptrack and downtrack tunnel might be constructed simultaneously. TBM ground-borne noise impacts from the construction of uptrack and downtrack tunnel were summed up logarithmically. As advised by MTR, two TBMs would be operated with at least 50m separation distance due to safety concern, therefore, the prediction was based on two operating TBMs with at least 50m apart.

Cumulative Effect due to Neighbouring Sites (C_cum)

5.6.13 Given that there would be no concurrent project that would induce ground-borne noise located in the vicinity of the Project, cumulative effect of construction ground-borne noise would not be anticipated.

Conversion to A-weighted Noise

5.6.14 With reference from the “Transit Noise and Vibration Impact Assessment”^{^[1]}, a conversion factor of -20 dB(A) was adopted in this prediction for conversion to A-weighted noise.

Operational Phase

5.6.15 The methodology for the vibration and ground-borne noise impact assessment was in accordance with the procedures outlined in U.S. Department of Transportation Federal Transit Administration (FTA) (FTA Guidance Manual) for detailed vibration analysis. This is a similar methodology as used for WIL, XRL and South Island Line (East) (SIL(E)) EIA Studies. The ground-borne noise levels in GBNSRs were calculated as follows:

L = FDL + TIL + TOC + TCF + LSR + BCF + BVR + CTN + SAF

where

L ground-borne noise level within building, in dB(A) re 20 μ-Pascal

FDL force density level, in dB re 1 N/m^0.5

TIL trackform attenuation or insertion loss, relative level

TOC turnout and crossover factor

TCF vibration coupling loss between the tunnel and the ground for soil based tunnels, relative level

LSR line source transfer mobility, in dB re 10^-⁹ m/s/(1 N/m^0.5)

BCF adjustment to account for building coupling loss, in dB

BVR building vibration amplification within the structure, in dB

CTN conversion from vibration to noise within the building, in dB re 10^-⁹ m/s to re 20 μ-Pascal

SAF safety factor to account for wheel/rail condition and uncertainties in ground conditions, in dB

Force Density Levels (FDL)

5.6.16 8-car type SP1900 or other train type with equivalent or better noise performance will be used in NOL. The vibration source levels (force density levels, FDL) was referenced from the FDL result measured in KSL EIA Study which is shown in metric units in Appendix 5.2.

5.6.17 According to Section 10.38 of the approved EIA report for Shatin to Central Link - Hung Hom to Admiralty Section [SCL (HUH-ADM)], the vibration source levels for the existing SP1900 EMU were obtained from passby measurements on the up track through Pat Heung Depot in previous rail projects. The deterioration in rail and rolling stock condition has already been taken into account in FDL obtained by measurements under rough rail condition. In accordance with the approved KSL EIA Report, comparisons of FDL obtained from the SP1900 EMU to other Hong Kong transit trains, including old East Rail EMU, as well as several other heavy rail EMUs in operation in the United States, indicated that the SP1900 FDL was 5 dB to 10 dB higher than the maximum FDL for the other trains. It was considered that the source term of SP1900 FDL is conservative and adopted in the NOL GBN assessment for conservative approach.

5.6.18 In accordance with Table 6-11 of the “High-Speed Ground Transportation Noise and Vibration Impact Assessment” (FTA Manual), the FDL was adjusted for speed as 20 log Speed/Speed_ref.

Trackform Alternatives or Insertion Loss (TIL)

5.6.19 Trackform attenuation has two components: the magnitude of the attenuation and the frequency above which attenuation occurs (resonance frequency of the trackform). Generally, more compliant trackform support and more massive elements in the trackform will result in a greater magnitude of attenuation occurring at lower frequencies.

5.6.20 According to the current design of the Project, Type 1a (Alt 1) trackform^{^[2]} would be adopted along the whole alignment, and therefore the adoption of Type 1a (Alt 1) trackform was considered as Base Case Scenario. If noise exceedances are predicted, mitigation measures such as low stiffness fasteners, floating slab track, etc will be proposed as necessary. The attenuations provided by different low noise trackforms were included in the calculation to determine the appropriate trackforms for meeting the criteria. The type of vibration mitigating trackform is listed below:

· Type 2: A high attenuation baseplate or booted dual sleepers: a bonded “Egg” style baseplate with a resilient elastomeric element having static stiffness in the range of 7 kN/mm to 14 kN/mm, to be fitted atop concrete sleepers or on the invert;

· Type 3: A floating slab trackform (FST) with loaded resonance frequency of about 16Hz.

Tunnel Coupling Factor (TCF)

5.6.21 Tunnel Coupling Factor (TCF) is the vibration coupling between the tunnel and the ground for soil based tunnels. Vibration attenuation occurs at the interface between a transit tunnel and the surrounding soil on account of a mismatch in the soil and tunnel wall impedances. The TCF to be adopted in this assessment was referenced from the previously approved EIA studies such as XRL and WIL EIA Studies. In general, tunnels borne in rock generally do not exhibit any significant vibration attenuation across the tunnel rock interface, thus no TCF attenuation is applied for rock-founded tunnels. However, with reference to the FTA Manual, a 3dB(A) and 5dB(A) reduction in ground-borne noise level were assumed for cut-and-cover tunnels and station structures respectively in soil.

5.6.22 For tunnels in soil, separate tests were carried out in Hong Kong, and these were reported in the WIL EIA study (Appendix 5.3 refers).

Turnout and Crossover Factor (TOC)

5.6.23 At points and crossings, where the wheel transitions from one rail to another, the sudden loading/unloading of the leading and trailing rails results in increased broad band vibration levels over that of plain line continuous rail. While it is not possible to machine grind the rails through either the points or crossings, surface deterioration would often be evident. For standard level turnouts and crossings receiving average maintenance, the FTA Manual recommends a correction of 10dB. For modern inclined turnouts in good condition, where impact loads are lessened, a correction of 5dB would be appropriate. In the WIL EIA study, 5dB(A) and 10dB(A) adjustment were added for inclined and vertical turnouts respectively. These corrections were also adopted in this assessment.

5.6.24 There would be turnouts and crossovers located at NOL alignment. An increase in ground-borne noise level of 10 dB(A) for each turnout was allowed in the assessment, assuming standard vertical turnouts.

Line Source Response (LSR)

5.6.25 The LSR determines the vibration levels or attenuation in the ground as a function of distance caused by an incoherent line source of unit force point impacts, with line source (train) orientated along the alignment. Thus, the basic quantity required for the determination of the LSR would be the vibration response caused by a unit point source impact, which is defined as the Point Source Response (PSR). Given that the PSR would be along the alignment, the LSR would follow directly by incoherent integration of the PSR values. However, the determination of the PSR for force point impacts along the alignment over the length of the alignment is neither practical nor affordable. For example, at underground sections, force impacting would have to be performed in numerous boreholes drilled to the depth of the alignment and closely spaced along the alignment. Thus, certain assumptions are invoked, which allow one PSR to be taken as representative along the alignment near a building receiver and to be used in the determination of the LSR. These assumptions include:

· ground is layer-wise homogeneous;

· ground is transversely isotropic along the alignment over the length of the train; and

· ground is between the alignment segment and the vibration receivers at which the LSR is to be determined.

5.6.26 If the ground satisfies these assumptions rigorously, it would be acceptable to use one PSR in the determination of the LSR. In normal circumstances, deviation from the idealized assumptions of transverse isotropy and layer-wise homogeneity is not significant enough to warrant the time, expense and impracticality of impacting along the entire length of the alignment.

5.6.27 The NOL tunnel will pass through mostly two types of ground condition (Appendix 2.1 refers): (1) soil (i.e. soft ground) which is a typical ground condition found in most of the area along the NOL alignment; and (2) rock (i.e. hard ground) which is a typical ground condition for the tunnel passing through hills and area near KSR Station. Borehole impact tests were therefore conducted at the areas with soil and rock type geology (i.e. near The Vineyard and KSR station respectively) to obtain respective LSR values. Details of the borehole impact test measurement and the measured LSR values for both types of ground condition are presented in Appendix 5.4. With due consideration of geological conditions along the alignment, the measured LSR values were adopted at different sections of the alignment, as presented in Appendix 5.5, to evaluate the ground-borne noise impact.

5.6.28 In addition, tunnel impact test would be conducted upon the completion of tunnel construction during which the LSR and TCF could be measured for providing a more accurate ground-borne noise prediction.

Building Coupling Factor (BCF)

5.6.29 In general, larger and heavier structures have greater vibration attenuation than smaller and lighter structures. The recommended practice established within FTA Manual was followed. Receivers in this assessment were divided into four types according to its structures and the associated BCF attenuation as below:

· Type 0 – Large masonry buildings

· Type 1 – 2 to 4 storeys masonry buildings

· Type 2 – 1 to 2 storeys buildings

· Type 3 – Single family detached residences

5.6.30 Appendix 5.6 presents the BCF for different types of structure and indicates that larger and heavier structures have greater vibration attenuation than smaller and lighter structures. In fact, the extent of the attenuation is governed by the difference in mechanical impedance between the soil and the foundation, with impedance being determined by differences in mass and stiffness within the soil and foundation. For structures founded on rock, there is no impedance contrast between the soil and the foundation and therefore the BCF is considered to be zero.

Building Vibration Response (BVR)

5.6.31 The BVR is generally determined by three factors as described below:

i. Resonance amplification due to floor, wall and ceiling spans: This resonance amplification is usually an issue for small and lightweight housing. In large, heavy framed structures, generally multi-floor concrete construction, structural resonances usually occur at sub-audible frequencies, with small resonance amplification due to massive structural elements having low mobility. FTA Manual recommends a 6 dB correction at the likely natural frequency of structures to account for structural resonances. The corrections in Appendix 5.7 were adopted, as was the case for the WIL EIA Study, as a conservative adaption of the 6dB correction.

ii. Floor-to-floor attenuation: A floor-to-floor attenuation of 2 dB reduction per floor was assumed. Where there is a multi-floor occupancy, only the structure borne noise impact on the lowest occupied floor was considered.

Conversion to Noise (CTN)

5.6.32 Based on FTA Manual, a -27 dB correction for conversion of vibration (re: 10^-9 m/s) in room walls, floors and ceiling to noise (re: 20 micro Pa) was assumed in this assessment.

Safety Factor

5.6.33 An attempt was made to estimate the other components of the prediction as accurately as possible, neither underestimating nor overestimating their effect. According to the approved EIA for Shatin to Central–Link - Tai Wai to Hung Hum Station (Register No.: AEIAR-167/2012) and Tung Chung Line Extension (Register No.: AEIAR-235/2022), a safety factor of 5 dB for GBNSRs could be adopted where site-specific LSR data is available and the use of measured FDL. Given that the site-specific LSR data and measured FDL are available, a 5 dB safety factor was adopted for evaluation of operational ground-borne noise impact.

Calculation of Operational Ground-borne Noise Impact

5.6.34 The calculation of the noise levels was based on the following assumptions:

· For the case where the tunnel will be in rock and the GBNSR is piled down to rock, the vibration path was assumed to be across the rock and up the piles into the building.

· For the cases where the tunnel will be in soft ground, the GBNSR is not on piles or the GBNSR is on piles not down to rock, the vibration path was assumed to be through the ground along a slant path to the nearest part of the GBNSR or piles.

· Where piling details are not known and the tunnel will be in rock, it was assumed that the piles are down to rock (worst case assumption).

5.6.35 Further to the operation details described in Section 2.3, the worst-case train operation mode are well defined and those parameters are listed in Table 5.6 below for the operational ground-borne noise assessment.

Table 5.6 Train Operation Parameters Adopted in Operational Ground-borne Noise Assessment

Item	Parameters
Item	Parameters
Train Type and No. of Car ⁽¹⁾	· Electric Multiple Unit Train, train length 200m for maximum 8-car train operation
Train Frequency/Movement	NOL Mainline: · 29 number per hour per direction during peak daytime and evening time periods. · 20 number per hour per direction during night-time period.
Speed Profile	Speed Profile of NOL is provided in Appendix 5.8.

Note:

(1) The train type, number of car and peak train frequencies were provided and confirmed by MTRCL.

5.6.36 Assessment of the worst-case operational scenario was carried out. Leq(30min) levels were calculated at the representative floor level (i.e. the lowest occupied floor) and the noise impact was quantified by indicating the total number of dwellings or other sensitive elements exposed to levels exceeding the criteria.

5.6.37 Operational ground-borne noise levels were calculated by incorporating the algorithms discussed in a 3-D model, MoleRat, which was also adopted in XRL ground-borne noise impact assessment and was accepted by EPD.

5.6.38 For evaluation of cumulative operational ground-borne noise from other existing railway projects, references were made to the approved EIA reports for XRL and LMCSL projects, where appropriate.

5.7 Evaluation of Environmental Impacts

Construction Phase

5.7.1 Potential ground-borne noise impacts on GBNSRs during the construction phase will arise mainly from the construction of tunnels and adits by use of TBM or the PME for rock breaking/drilling at drill-and-blast tunnel/adits. It is anticipated that there is only a representative construction phasing (i.e. along the alignment/adits) during the construction of tunnels and adits that would induce ground-borne noise impact to the GBNSRs.

5.7.2 The standard working hours of PME will be from 0700 to 1900 hours and the TBM will be operated on a 24 hour basis. The operation of TBM during restricted hours should be governed by the control of CNP under NCO. Despite any description or assessment made in this EIA Report on construction noise aspects, there is no guarantee that a CNP will be issued for the Project construction. The Noise Control Authority will consider a well-justified CNP application, once filed, for construction works within restricted hours as guided by the relevant TMs issued under the NCO. This ground-borne noise impact assessment for construction phase is hence conducted for the non-restricted hours period only. The construction methods to be adopted at different locations of the Project were illustrated in Figure No. C1603/C/NOL/ACM/M50/305.

5.7.3 Any blasting activities, if required, would be carried out underground. Any such blasting noise, which is transient and short in duration, was not assessed. The blasting activity is not governed by NCO and EIAO. However, the administrative and procedural control of all blasting operations in Hong Kong is vested by the Mines Division of the Civil Engineering and Development Department (CEDD).

5.7.4 Ground-borne noise levels at the representative GBNSRs associated with the use of PME for rock breaking/drilling works and TBM were predicted and are summarized in Table 5.7 and Table 5.8 respectively. Detailed GBN calculations and assumptions for PME and TBM operation are provided in Appendix 5.9 and Appendix 5.10 respectively.

Table 5.7 Predicted Construction Ground-borne Noise Impact from PME Operation

GBNSR ID	Description	Land Use⁽¹⁾	Predicted Ground-borne Noise Levels L_eq(30min), dB(A)	Daytime Criterion, L_eq(30min)dB(A)	Compliance
AUT-G11	169 Pok Wai	R	63	65	Yes
NTM-G07	Village House near Wang Ping Shan South Road	R	51	65	Yes
NTM-G08	Village House near Wang Ping Shan South Road	R	55	65	Yes
NTM-G09	Village House in Long Ha	R	50	65	Yes

Note:

(1) R – Residential.

Table 5.8 Predicted Construction Ground-borne Noise Impact from TBM Operation

GBNSR ID	Description	Land Use⁽¹⁾	Predicted Ground-borne Noise Levels L_eq(30min), dB(A)	Daytime Noise Criterion, L_eq(30min),dB(A)	Compliance
Existing GBNSRs
KSR-G01	No.110 Cheung Chun San Tsuen	R	58	65	Yes
KSR-G02	Blk 77, Sam Yuen	R	46	65	Yes
KSR-G03	Kam Tin Mung Yeung Public School	E	49	60 (55 during Exams)	Yes
KSR-G04	No.297-298 Kut Hing Wai	R	55	65	Yes
KSR-G05	Kat Hing Garden	R	62	65	Yes
AUT-G01	No. 173, Mo Fan Heung	R	59	65	Yes
AUT-G02	No. 137, Mo Fan Heung	R	63	65	Yes
AUT-G03	No. 80, Mo Fan Heung	R	62	65	Yes
AUT-G06	Tower 2B, Park Yoho Silica	R	55	65	Yes
AUT-G07	Tower 9B, Park Vista	R	56	65	Yes
AUT-G08	Tower 8B, Park Yoho	R	55	65	Yes
AUT-G09	In Keen Garden Phase 1	R	50	65	Yes
AUT-G10	York International Kindergarten ⁽²⁾	E	59	60	Yes
NTM-G01	The Vineyard	R	54	65	Yes
NTM-G02	China Bible Seminary	E	55	60 (55 during Exams)	Yes
NTM-G03	House A, Greenacres Villa	R	58	65	Yes
NTM-G04	Hongtai Home for the Aged Limited	EC	57	65	Yes
NTM-G04a	Temporary Structure near Ching Yau Road	R	60	65	Yes
NTM-G06	Village House near Fuk Hing Lei	R	58	65	Yes
NTM-G07	Village House near Wang Ping Shan South Road	R	60	65	Yes
NTM-G08	Village House near Wang Ping Shan South Road	R	48	65	Yes
SAT-G03	Temporary Structure near Shek Wu Wai	R	59	65	Yes
KTU-G01	Village House in Chau Tau Tsuen	R	48	65	Yes
KTU-G02	Village House in Chau Tau Tsuen	R	60	65	Yes
Planned GBNSRs
KSR-PG01a	Planned School in Park Yoho Phase 3	E	57	60 (55 during Exams)	No (2 dB(A) exceedance during Exams)
KSR-PG01b	Proposed Residential Development in Park Yoho Phase 3	R	56	65	Yes
KSR-PG01c	Proposed Residential Development Park Yoho Phase 2	R	57	65	Yes
KSR-PG01d	Planned School in Park Yoho Phase 3	E	60	60 (55 during Exams)	No (5 dB(A) exceedance during Exams)
KSR-PG02	Proposed Residential Development at Kam Tin North	R	64	65	Yes
AUT-PG01	Planned Residential Block at Sha Po Public Housing Development	R	59	65	Yes
AUT-PG03	Planned Residential Block at Sha Po Public Housing Development	R	57	65	Yes
KTU-PG01	Planned Housing Development at Kwu Tung North NDA	R	46	65	Yes
KTU-PG01a	Planned Housing Development at Kwu Tung North NDA	R	55	65	Yes

Notes:

(1) R – Residential; EC – Elderly Centre; E – Educational institutions.

(2) No examination period would be anticipated at kindergarten.

(3) Numbers in bold and underlined indicate exceedances of the noise criterion.

5.7.5 Predicted results indicate that the TBM and PME induced ground-borne noise levels would comply with the daytime criteria at the representative GBNSRs, while a planned school site would be subject up to 5 dB(A) exceedance during examination period due to TBM operation in the vicinity. The Contractor should closely liaise with the representatives of the education institution to confirm the examination periods, so as to avoid TBM operation in the vicinity of the school within such periods.

5.7.6 There could be potential cumulative construction ground-borne noise impact at GBNSR NTM-G07 and NTM-G08 if both TBM and drill-and-blast tunnelling works to be conducted simultaneously. The predicted cumulative construction ground-borne noise levels at GBNSR NTM-G07 and NTM-G08 are 60 dB(A) and 56 dB(A) respectively, complying with stipulated noise limit, and thus no adverse cumulative construction ground-borne noise impact is expected.

Table 5.9 Predicted Cumulative Construction Ground-borne Noise Impact

GBNSR ID	Predicted Ground-borne Noise Levels L_eq(30min), dB(A)		Total	Daytime Criterion, L_eq(30min)dB(A)	Compliance
GBNSR ID	TBM	PME	Total	Daytime Criterion, L_eq(30min)dB(A)	Compliance
NTM- G07	60	51	60	65	Yes
NTM-G08	48	55	56	65	Yes

Operational Phase

Base Case Scenario

5.7.7 The predicted ground-borne railway noise levels at the lowest occupied floor of GBNSRs under Base Case Scenario are shown in Table 5.10. Adopted trackform insertion losses are presented in Appendix 5.11. Sample calculations are provided in Appendix 5.12. The predicted ground-borne railway noise levels at the NSRs at various representative floor levels are presented in Appendix 5.13. The predicted operational ground-borne noise levels at all the representative GBNSRs comply with the noise criteria.

Table 5.10 Predicted Ground-borne Railway Noise Impact under Base Case Scenario

GBNSR ID	Description	Land Use⁽¹⁾	ASR	Predicted Ground-borne Railway Noise Levels, L_eq(30min, dB(A)		Criteria, L_eq(30min),dB(A)		Compliance (Yes/No)
GBNSR ID	Description	Land Use⁽¹⁾	ASR	Day/Evening (0700-2300 hrs)	Night (2300-0700 hrs)	Day/Evening (0700-2300 hrs)	Night (2300-0700 hrs)	Day/Evening (0700-2300 hrs)	Night (2300-0700 hrs)
Existing GBNSRs
KSR-G01	No.110 Cheung Chun San Tsuen	R	A	22	20	50	40	Yes	Yes
KSR-G02	Blk 77, Sam Yuen	R	A	<20	<20	50	40	Yes	Yes
KSR-G03	Kam Tin Mung Yeung Public School	E	A	20	- ⁽³⁾	50	- ⁽³⁾	Yes	- ⁽³⁾
KSR-G04	No.297-298 Kut Hing Wai	R	A	22	21	50	40	Yes	Yes
KSR-G05	Kat Hing Garden	R	A	24	23	50	40	Yes	Yes
AUT-G01	No. 173, Mo Fan Heung	R	B	26	24	55	45	Yes	Yes
AUT-G02	No. 137, Mo Fan Heung	R	B	29	27	55	45	Yes	Yes
AUT-G03	No. 80, Mo Fan Heung	R	B	26	24	55	45	Yes	Yes
AUT-G06	Tower 2B, Park Yoho Silica	R	B	<20	<20	55	45	Yes	Yes
AUT-G07	Tower 9B, Park Vista	R	B	<20	<20	55	45	Yes	Yes
AUT-G08	Tower 8B, Park Yoho	R	B	<20	<20	55	45	Yes	Yes
AUT-G09	In Keen Garden Phase 1	R	B	<20	<20	55	45	Yes	Yes
AUT-G10	York International Kindergarten ⁽²⁾	E	B	23	- ⁽³⁾	55	- ⁽³⁾	Yes	- ⁽³⁾
NTM-G01	The Vineyard	R	A	<20	<20	50	40	Yes	Yes
NTM-G02	China Bible Seminary	E	A	<20	- ⁽³⁾	50	- ⁽³⁾	Yes	- ⁽³⁾
NTM-G03	House A, Greenacres Villa	R	A	<20	<20	50	40	Yes	Yes
NTM-G04	Hongtai Home for the Aged Limited	EC	B	<20	<20	55	45	Yes	Yes
NTM-G04a	Temporary Structure near Ching Yau Road	R	B	24	22	55	45	Yes	Yes
NTM-G06	Village House near Fuk Hing Lei	R	A	21	<20	50	40	Yes	Yes
NTM-G07	Village House near Wang Ping Shan South Road	R	B	20	<20	55	45	Yes	Yes
NTM-G08	Village House near Wang Ping Shan South Road	R	B	<20	<20	55	45	Yes	Yes
KTU-G01	Village House in Chau Tau Tsuen	R	A	<20	<20	50	40	Yes	Yes
KTU-G02	Village House in Chau Tau Tsuen	R	B	27	25	55	45	Yes	Yes
Planned GBNSRs
KSR-PG01a	Planned School in Park Yoho Phase 3	E	B	<20	- ⁽³⁾	55	- ⁽³⁾	Yes	- ⁽³⁾
KSR-PG01b	Proposed Residential Development in Park Yoho Phase 3	R	B	<20	<20	55	45	Yes	Yes
KSR-PG01c	Proposed Residential Development Park Yoho Phase 2	R	B	<20	<20	55	45	Yes	Yes
KSR-PG01d	Planned School in Park Yoho Phase 3	E	B	25	- ⁽³⁾	55	- ⁽³⁾	Yes	- ⁽³⁾
KSR-PG02	Kam Tai Road Residential Development	R	A	34	33	50	40	Yes	Yes
KSR-PG03	Grand Mayfair (under Construction)	R	B	25	24	55	45	Yes	Yes
KSR-PG04	Future Kam Sheung Road Package 2 Property Development	R	B	35	33	55	45	Yes	Yes
KSR-PG05a	Planned G/IC Site at Kam Tin South Housing Development	G/IC	B	32	30	55	45	Yes	Yes
KSR-PG05b	Planned Residential Block at Kam Tin South Housing	R	B	25	23	55	45	Yes	Yes
KSR-PG06a	Planned G/IC Site at Kam Tin South Housing Development	G/IC	B	28	26	55	45	Yes	Yes
KSR-PG06b	Planned School Site at Kam Tin South Housing Development	E	B	47	- ⁽³⁾	55	- ⁽³⁾	Yes	- ⁽³⁾
KSR-PG06c	Planned Residential Block at Kam Tin South Housing Development	R	B	32	30	55	45	Yes	Yes
AUT-PG01	Planned Residential Block at Sha Po Public Housing Development	R	B	20	<20	55	45	Yes	Yes
AUT-PG03	Planned Residential Block at Sha Po Public Housing Development	R	B	<20	<20	55	45	Yes	Yes
NTM-PG01	Potential Development at Land Use Review Study for Ngau Tam Mei Area	R	B	<20	<20	55	45	Yes	Yes
SAT-PG01a	Potential Housing Development in San Tin / Lok Ma Chau Development Node (STLMC DN)	R	B	25	23	55	45	Yes	Yes
SAT-PG01b	Potential Housing Development in STLMC DN Node	R	B	20	<20	55	45	Yes	Yes
SAT-PG01c	Potential Housing Development in STLMC DN	R	B	27	25	55	45	Yes	Yes
SAT-PG01d	Potential Housing Development in STLMC DN	R	B	35	33	55	45	Yes	Yes
SAT-PG01e	Potential Housing Development in STLMC DN	R	B	<20	<20	55	45	Yes	Yes
SAT-PG01f	Potential Housing Development in STLMC DN	R	B	24	22	55	45	Yes	Yes
SAT-PG01g	Potential Housing Development in STLMC DN	R	B	<20	<20	55	45	Yes	Yes
SAT-PG01h	Potential Housing Development in STLMC DN	R	B	28	26	55	45	Yes	Yes
SAT-PG01i	Potential Housing Development in STLMC DN	R	B	25	23	55	45	Yes	Yes
SAT-PG01j	Potential Housing Development in STLMC DN	R	B	30	28	55	45	Yes	Yes
SAT-PG01k	Potential Cultural & Recreational Complex in STLMC DN	G/IC	B	<20	- ⁽³⁾	55	- ⁽³⁾	Yes	- ⁽³⁾
SAT-PG02	Potential Cultural & Recreational Complex in STLMC DN	G/IC	B	<20	- ⁽³⁾	55	- ⁽³⁾	Yes	- ⁽³⁾
SAT-PG02a	Potential GIC Facility in STLMC DN	G/IC	B	<20	<20	55	45	Yes	Yes
SAT-PG03a	Potential School in STLMC DN	E	B	<20	- ⁽³⁾	55	- ⁽³⁾	Yes	- ⁽³⁾
SAT-PG03b	Potential School in STLMC DN	E	B	<20	- ⁽³⁾	55	- ⁽³⁾	Yes	- ⁽³⁾
SAT-PG03c	Potential GIC Facility in STLMC DN	G/IC	B	25	23	55	45	Yes	Yes
SAT-PG03d	Potential FSD Staff Quarter in STLMC DN	R	B	<20	<20	55	45	Yes	Yes
KTU-PG01	Planned Housing Development at Kwu Tung North	R	B	<20	<20	55	45	Yes	Yes
KTU-PG01a	Planned Housing Development at Kwu Tung North	R	B	22	20	55	45	Yes	Yes
KTU-PG02	Planned Housing Development at Kwu Tung North	R	B	<20	<20	55	45	Yes	Yes
KTU-PG02a	Planned Housing Development at Kwu Tung North	R	B	24	23	55	45	Yes	Yes
KTU-PG03	Planned Housing Development at Kwu Tung North	R	B	<20	<20	55	45	Yes	Yes
KTU-PG03a	Planned Housing Development at Kwu Tung North	R	B	<20	<20	55	45	Yes	Yes

Notes:

(1) R – Residential; EC – Elderly Centre; E – Educational institutions; G/IC – Government, Institution or Community.

(2) Information subject to the design of planned development.

(3) No sensitive use is anticipated during night-time period.

5.8 Recommended Mitigation Measures

Construction Phase

5.8.1 The construction ground-borne noise levels would comply with the stipulated noise criteria at all GBNSRs, except a planned school site would subject to up to 5 dB(A) exceedance during examination period. The Contractor should closely liaise with the representative of the education institution to confirm the examination periods, so as to avoid TBM operation in the vicinity of the school within such periods. The operation of TBM during restricted hours should be subject to the control of CNP under NCO.

Operational Phase

5.8.2 The operational ground-borne noise levels at all GBNSRs would comply with statutory noise criteria. Therefore, the use of the proposed trackform (i.e. Type 1a (Alt 1) trackform stated in Section 5.6.20) would be sufficient to achieve the relevant noise criteria and upgrade of low vibration trackform would not be required.

5.8.3 Nonetheless, the trackform would be further reviewed based on the findings of tunnel impact test to be conducted after the completion of tunnel construction.

5.9 Cumulative Impacts from Existing Railway Projects

5.9.1 Some tunnel sections of the Project would be located close to other existing railway projects including HSR and LMCSL, and therefore potential cumulative ground-borne noise impact from HSR and LMCSL would be expected.

HSR

5.9.2 GBNSRs at Ngau Tam Mei area may be potentially affected by the cumulative railway GBN impact. According to Table 6.15 of the approved EIA report for XRL (Register No.: AEIAR-143/2009), the unmitigated GBN railway impacts at Ngau Tam Mei area (e.g. GBNSR No. GN36, 37, 37a (See Table 6.15 of approved EIA report for XRL)) were predicted less than 21 dB(A) and 16 dB(A) during day/evening and night-time respectively. In addition, given that the GBN impacts arisen from the Project under Base Case Scenario at the representative GBNSRs (i.e. NTM-G02, NTM-G03 and NTM-PG-01) were predicted less than 20 dB(A) during day/evening and night-time respectively, it is envisaged that the cumulative railway GBN impact would be insignificant.

LMCSL

5.9.3 GBNSRs at Kwu Tung North area may be potentially affected by the cumulative railway GBN impact. Under the Base Case Scenario of the Project, the operational ground-borne noise levels at the representative GBNSRs (KTU-G01, KTU-G02, KTU-PG01, KTU-PG01a, KTU-PG02, KTU-PG02a, KTU-PG03 and KTU-PG03a), which are located in the vicinity of NOL and LMCSL, were predicted up to 25 dB(A) during night-time period. Given that the predicted GBN impact arising from the Project is at least 10 dB(A) below ANL, no adverse cumulative GBN impact is anticipated.

5.9.4 The potential cumulative ground-borne railway noise impact is summarized in Table 5.11.

Table 5.11 Cumulative Ground-borne Railway Noise Impact

GBNSR ID	Predicted Ground-borne Noise Levels L_eq(30min), dB(A)		Cumulative GBN Levels, dB(A)	Nose Criterion, L_eq(30min)dB(A)	Compliance
GBNSR ID	NOL	Existing Railway	Cumulative GBN Levels, dB(A)	Nose Criterion, L_eq(30min)dB(A)	Compliance
Daytime and Evening Period (0700-2300 hours)
NTM- G02	<20	<30 ⁽¹⁾	<30 ⁽²⁾	50	Yes
NTM- G03	<20	<30 ⁽¹⁾	<30 ⁽²⁾	50	Yes
NTM- PG01	<20	<30 ⁽¹⁾	<30 ⁽²⁾	55	Yes
KTU-G01	<20	(3)	At least 10dB(A) below noise criterion ⁽²⁾	50	Yes
KTU-G02	27			55	Yes
KTU-PG01	<20			55	Yes
KTU-PG01a	22			55	Yes
KTU-PG02	<20			55	Yes
KTU-PG02a	24			55	Yes
KTU-PG03	<20			55	Yes
KTU-PG03a	<20			55	Yes
Night-time Period (2300-0700 hours)
NTM- G02	- ⁽⁴⁾	- ⁽⁴⁾	- ⁽⁴⁾	- ⁽⁴⁾	- ⁽⁴⁾
NTM- G03	<20	<20⁽¹⁾	<23 ⁽²⁾	40	Yes
NTM- PG01	<20	<20⁽¹⁾	<23 ⁽²⁾	45	Yes
KTU-G01	<20	(3)	At least 10dB(A) below noise criterion ⁽²⁾	40	Yes
KTU-G02	25			45	Yes
KTU-PG01	<20			45	Yes
KTU-PG01a	20			45	Yes
KTU-PG02	<20			45	Yes
KTU-PG02a	23			45	Yes
KTU-PG03	<20			45	Yes
KTU-PG03a	<20			45	Yes

Notes:

(1) According to Table 6.15 of the approved EIA report for XRL, the unmitigated GBN railway impacts at Ngau Tam Mei area (e.g. GBNSR No. GN36, 37, 37a (See Table 6.15 of approved EIA report for XRL)) were predicted less than 21 dB(A) and 16 dB(A) during day/evening and night-time respectively.

(2) As the predicted railway ground-borne noise impact arising from the Project is at least 10 dB(A) below ANL, no adverse cumulative GBN impact is anticipated.

(3) No quantitative ground-borne noise assessment was performed in the approved EIA report of LMCSL. Nevertheless, as the predicted railway ground-borne noise impact arising from the Project is at least 10 dB(A) below ANL, no adverse cumulative GBN impact is anticipated.

(4) No sensitive use is anticipated during night-time period.

5.10 Evaluation of Residual Impacts

5.10.1 No residual ground-borne noise impact due to the construction of the Project provided that the recommended mitigation measure is implemented.

5.10.2 No residual ground-borne noise impact due to the operation of the Project is anticipated.

5.11 EM&A Requirements

Construction Phase

5.11.1 The predicted ground-borne noise levels comply with the stipulated daytime noise criteria without noise mitigation measures, except at a planned school site during examination period. Given that the Contractor would closely liaise with the representative of the education institution to confirm the examination periods, so as to avoid TBM operation in the vicinity of the school within such periods, ground-borne noise monitoring is considered not necessary during construction phase.

5.11.2 Tunnel impact test would be conducted upon the completion of tunnel construction during which the LSR and TCF could be measured for providing a more accurate ground-borne noise prediction. This will also allow updating of the ground-borne noise predictions and the recommendation on mitigation measures for operational phase as necessary.

5.11.3 An Environmental Monitoring and Audit (EM&A) programme is recommended to be developed with details of the EM&A requirements are provided in a stand-alone EM&A Manual.

Operational Phase

5.11.4 Prior to the operation of the Project, a commissioning test will be conducted to ensure compliance of the operational ground-borne noise levels with the noise criteria. Details of the test requirements are provided in a stand-alone EM&A Manual.

5.12 Conclusions

Construction Phase

5.12.1 Predicted results indicate that the PME and TBM induced ground-borne noise levels comply with the daytime criteria at the representative GBNSRs, except that a planned school site may be subject to ground-borne noise levels exceeding the daytime noise limit during examination period. No adverse cumulative construction ground-borne noise impact was predicted at the locations where PME and TBM would be potentially carried out simultaneously.

Operational Phase

5.12.2 During operational phase, with the adoption of Type 1a (Alt 1) trackform as the base case scenario, the predicted ground-borne noise levels at all the representative GBNSRs comply with the stipulated noise limits. Potential cumulative impact arising from the Project and existing rail lines (i.e. HSR (i.e. formerly named as XRL) and LMCSL) was reviewed and no adverse cumulative impact would be anticipated.

5.12.3 Further review on the ground-borne noise predictions would be conducted and any update on the trackform would be proposed according to the findings of tunnel impact test to be conducted upon the completion of tunnel construction during which the LSR and TCF could be measured for providing a more accurate ground-borne noise prediction.

^{^[2]}Type 1a: A medium attenuation baseplate or booted dual sleepers based on a bonded or non-bonded compression style baseplate with a resilient elastomeric element having static stiffness of about 25 kN/mm, to be fitted atop the concrete sleepers or atop the invert.

Appendix 5.1	Not Used
Appendix 5.2	Force Density Level of Train Type SP1900
Appendix 5.3	Tunnel Coupling Factor for Bored Tunnel in Soil
Appendix 5.4	Noise Measurement Report for Line Source Response (LSR) for Different Ground Types
Appendix 5.5	Adopted LSR Values for Ground-borne Noise Assessment
Appendix 5.6	Building Coupling Factor – Type 0 to Type 3 Structures
Appendix 5.7	Building Vibration Response
Appendix 5.8	Train Speed Profile
Appendix 5.9	GBN Calculation for PME Operation
Appendix 5.10	GBN Calculation for TBM Operation
Appendix 5.11	Trackform Insertion Loss
Appendix 5.12	Sample Calculation for Operational Ground-borne Railway Noise (Base Case Scenario)
Appendix 5.13	Predicted Ground-borne Railway Noise Levels at the NSRs at Representative Floor Levels

5 Ground-borne Noise Impact

5.1.1 This section presents an assessment of the potential ground-borne noise (GBN) impacts associated with construction and operation of the Project.

5.1.3 Recommendations for mitigation measures were provided to minimize the identified ground-borne noise impacts.

5.2 Environmental Legislation, Plans, Standards, and Guidelines

5.2.1 Construction ground-borne noise is under the control of the Noise Control Ordinance (NCO), the Environmental Impact Assessment Ordinance (EIAO), and their subsidiary Technical Memorandum.

5.2.4 The construction ground-borne noise criteria for the identified ground-borne noise sensitive receivers (GBNSRs) are tabulated in Table 5.1 below.

Operational Phase

5.4 Sources of Impact

Construction Phase

5.4.2 Based on the best available information at the time of preparation of this EIA report, potential cumulative construction ground-borne noise from concurrent projects is not anticipated.

Operational Phase

5.6.2 The main components of the proposed construction ground-borne noise assessment methodology are:

5.6.3 The vibration level Lv,rms at a distance R from the source is related to the vibration source level at a reference distance R0. The conversion from vibration levels to ground-borne noise levels was determined by the following factors:

5.6.4 The ground-borne noise level (Lp) inside the GBNSR was predicted using the following equation:

5.6.5 The assessment was based on worst-case assumptions with the details of the assumptions described in the following sections.

Reference Vibration Sources

Distance Attenuation (Cdist)

5.6.7 Ground-borne noise can be attenuated by longer distance of vibration energy transmission pathway. The following equation was used to evaluate the distance attenuation factor (Cdist):

where

R separation between the tunnel boundary and the GBNSR

R0 reference distance of the vibration measurement (i.e. 5.5m)

Soil Damping (Cdamping)

5.6.8 No damping attenuation was adopted in this assessment as conservative approach.

Coupling Loss into Building Foundation, (Cbuilding)

5.6.9 The coupling loss into building structures represents the change in the incident ground-surface vibration due to the presence of the piled building foundation. The correction factor was assumed to be zero in this assessment as conservative approach.

Coupling Loss per Floor (Cfloor)

Conversion from Floor Vibration to Noise Levels (Cnoise)

5.6.11 A -27dB correction was assumed for conversion of vibration to noise (re. 20μPa) for residential units and school and this is in line with the previous approved EIA report.

Noise Level Increase due to Multiple Sources (Cmulti)

Cumulative Effect due to Neighbouring Sites (Ccum)

5.6.13 Given that there would be no concurrent project that would induce ground-borne noise located in the vicinity of the Project, cumulative effect of construction ground-borne noise would not be anticipated.

Conversion to A-weighted Noise

5.6.14 With reference from the “Transit Noise and Vibration Impact Assessment”[1], a conversion factor of -20 dB(A) was adopted in this prediction for conversion to A-weighted noise.

L = FDL + TIL + TOC + TCF + LSR + BCF + BVR + CTN + SAF

where

L ground-borne noise level within building, in dB(A) re 20 μ-Pascal

FDL force density level, in dB re 1 N/m0.5

TIL trackform attenuation or insertion loss, relative level

TOC turnout and crossover factor

TCF vibration coupling loss between the tunnel and the ground for soil based tunnels, relative level

LSR line source transfer mobility, in dB re 10-9 m/s/(1 N/m0.5)

BCF adjustment to account for building coupling loss, in dB

BVR building vibration amplification within the structure, in dB

CTN conversion from vibration to noise within the building, in dB re 10-9 m/s to re 20 μ-Pascal

SAF safety factor to account for wheel/rail condition and uncertainties in ground conditions, in dB

Force Density Levels (FDL)

5.6.16 8-car type SP1900 or other train type with equivalent or better noise performance will be used in NOL. The vibration source levels (force density levels, FDL) was referenced from the FDL result measured in KSL EIA Study which is shown in metric units in Appendix 5.2.

5.6.18 In accordance with Table 6-11 of the “High-Speed Ground Transportation Noise and Vibration Impact Assessment” (FTA Manual), the FDL was adjusted for speed as 20 log Speed/Speedref.

Trackform Alternatives or Insertion Loss (TIL)

· Type 2: A high attenuation baseplate or booted dual sleepers: a bonded “Egg” style baseplate with a resilient elastomeric element having static stiffness in the range of 7 kN/mm to 14 kN/mm, to be fitted atop concrete sleepers or on the invert;

· Type 3: A floating slab trackform (FST) with loaded resonance frequency of about 16Hz.

Tunnel Coupling Factor (TCF)

5.6.22 For tunnels in soil, separate tests were carried out in Hong Kong, and these were reported in the WIL EIA study (Appendix 5.3 refers).

Turnout and Crossover Factor (TOC)

5.6.24 There would be turnouts and crossovers located at NOL alignment. An increase in ground-borne noise level of 10 dB(A) for each turnout was allowed in the assessment, assuming standard vertical turnouts.

Line Source Response (LSR)

· ground is layer-wise homogeneous;

· ground is transversely isotropic along the alignment over the length of the train; and

· ground is between the alignment segment and the vibration receivers at which the LSR is to be determined.

5.6.28 In addition, tunnel impact test would be conducted upon the completion of tunnel construction during which the LSR and TCF could be measured for providing a more accurate ground-borne noise prediction.

Building Coupling Factor (BCF)

· Type 0 – Large masonry buildings

· Type 1 – 2 to 4 storeys masonry buildings

· Type 2 – 1 to 2 storeys buildings

· Type 3 – Single family detached residences

Building Vibration Response (BVR)

5.6.31 The BVR is generally determined by three factors as described below:

ii. Floor-to-floor attenuation: A floor-to-floor attenuation of 2 dB reduction per floor was assumed. Where there is a multi-floor occupancy, only the structure borne noise impact on the lowest occupied floor was considered.

Conversion to Noise (CTN)

5.6.32 Based on FTA Manual, a -27 dB correction for conversion of vibration (re: 10-9 m/s) in room walls, floors and ceiling to noise (re: 20 micro Pa) was assumed in this assessment.

Safety Factor

Calculation of Operational Ground-borne Noise Impact

5.6.34 The calculation of the noise levels was based on the following assumptions:

· For the case where the tunnel will be in rock and the GBNSR is piled down to rock, the vibration path was assumed to be across the rock and up the piles into the building.

· For the cases where the tunnel will be in soft ground, the GBNSR is not on piles or the GBNSR is on piles not down to rock, the vibration path was assumed to be through the ground along a slant path to the nearest part of the GBNSR or piles.

· Where piling details are not known and the tunnel will be in rock, it was assumed that the piles are down to rock (worst case assumption).

5.6.37 Operational ground-borne noise levels were calculated by incorporating the algorithms discussed in a 3-D model, MoleRat, which was also adopted in XRL ground-borne noise impact assessment and was accepted by EPD.

5.6.38 For evaluation of cumulative operational ground-borne noise from other existing railway projects, references were made to the approved EIA reports for XRL and LMCSL projects, where appropriate.

Base Case Scenario

5.8 Recommended Mitigation Measures

5.6.3 The vibration level L_v,rmsat a distance R from the source is related to the vibration source level at a reference distance R₀. The conversion from vibration levels to ground-borne noise levels was determined by the following factors:

5.6.4 The ground-borne noise level (L_p) inside the GBNSR was predicted using the following equation:

Distance Attenuation (C_dist)

5.6.7 Ground-borne noise can be attenuated by longer distance of vibration energy transmission pathway. The following equation was used to evaluate the distance attenuation factor (C_dist):

R₀ reference distance of the vibration measurement (i.e. 5.5m)

Soil Damping (C_damping)

Coupling Loss into Building Foundation, (C_building)

Coupling Loss per Floor (C_floor)

Conversion from Floor Vibration to Noise Levels (C_noise)

Noise Level Increase due to Multiple Sources (C_multi)

Cumulative Effect due to Neighbouring Sites (C_cum)

5.6.14 With reference from the “Transit Noise and Vibration Impact Assessment”^{^[1]}, a conversion factor of -20 dB(A) was adopted in this prediction for conversion to A-weighted noise.

FDL force density level, in dB re 1 N/m^0.5

LSR line source transfer mobility, in dB re 10^-⁹ m/s/(1 N/m^0.5)

CTN conversion from vibration to noise within the building, in dB re 10^-⁹ m/s to re 20 μ-Pascal

5.6.18 In accordance with Table 6-11 of the “High-Speed Ground Transportation Noise and Vibration Impact Assessment” (FTA Manual), the FDL was adjusted for speed as 20 log Speed/Speed_ref.

5.6.32 Based on FTA Manual, a -27 dB correction for conversion of vibration (re: 10^-9 m/s) in room walls, floors and ceiling to noise (re: 20 micro Pa) was assumed in this assessment.