Noise and vibration part 1 - Auckland Transport document may not be reproduced in full or in part without the written consent of Marshall Day Acoustics Limited C:\Users\GeorgiaS1\Desktop\new

City Rail Link

Noise and Vibration Assessment

Report No.: 001 R07 2012068A

13 August 2012

84 Symonds Street PO Box 5811 Wellesley Street Auckland 1141 New Zealand

T: +64 9 379 7822 F: +64 9 309 3540 www.marshallday.com

Technical Report Revision History

Status: Rev: Comments Date: Author: Reviewer:

Draft - Preliminary Draft Noise and Vibration Report

30-3-2012

Steve Peakall Craig Fitzgerald James Whitlock Siiri Wilkening

Draft 1 Final Draft Noise and Vibration Report

8-6-2012 Steve Peakall Craig Fitzgerald James Whitlock

Curt Robinson Graham Warren

Draft 2 Noise and Vibration Report

20-6-2012

Steve Peakall Craig Fitzgerald James Whitlock Mike Carter

Final Draft 3 Noise and Vibration Report Revision

6-7-2012 Craig Fitzgerald James Whitlock

Curt Robinson

Approved 4 Final 31-7-2012 Craig Fitzgerald James Whitlock

Approved 5 Final 13-8-2012 Craig Fitzgerald James Whitlock

Approved 6 Post AC review 9-11-2012 James Whitlock

Approved 7 NoR 7 removal and NoR 6 optimisation changes

10-12-2012 Craig Fitzgerald James Whitlock

Technical Report Review and Acceptance

Action Name Signed Date

Prepared by Craig Fitzgerald 10-12-2012

James Whitlock

Reviewed by Curt Robinson 10-12-2012

Approved by Curt Robinson 10-12-2012

On behalf of Marshall Day Acoustics

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This document may not be reproduced in full or in part without the written consent of Marshall Day Acoustics Limited

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TABLE OF CONTENTS

1. GLOSSARY OF TERMS ............................................................................................................... 4

2. EXECUTIVE SUMMARY ............................................................................................................. 6

3. PROJECT DESCRIPTION ............................................................................................................ 7

4. TECHNICAL ASSESSMENT METHODOLOGY ............................................................................ 7

4.1 Noise .......................................................................................................................................... 7

4.2 Vibration ................................................................................................................................... 8

5. EXISTING ENVIRONMENT ........................................................................................................ 9

5.1 Existing Noise Environment ..................................................................................................... 9

5.2 Existing Vibration Environment ............................................................................................. 12

6. NOISE AND VIBRATION PERFORMANCE STANDARDS......................................................... 15

6.1 Literature review .................................................................................................................... 15

6.2 Project Criteria - Construction Phase .................................................................................... 15

6.3 Project Criteria - Operational Phase ..................................................................................... 19

7. ASSESSMENT OF EFFECTS ON THE ENVIRONMENT AND MITIGATION OPTIONS CONSTRUCTION PHASE .......................................................................................................... 21

7.1 Construction Noise ................................................................................................................. 21

7.2 Construction Vibration ........................................................................................................... 28

7.3 Options for Avoiding, Remedying or Mitigating Adverse Construction Effects ................. 34

7.4 Construction Noise and Vibration Management Plan (CNVMP) ........................................ 34

8. ASSESSMENT OF EFFECTS ON THE ENVIRONMENT AND MITIGATION OPTIONS OPERATIONAL PHASE ............................................................................................................. 35

8.1 Operational Noise .................................................................................................................. 35

8.2 Operational Vibration and Reradiated Noise ....................................................................... 37

8.3 Options for Avoiding, Remedying or Mitigating Adverse Operation Effects ..................... 39

9. CONCLUSION .......................................................................................................................... 40

APPENDIX A REVIEW OF CONSTRUCTION NOISE CRITERIA

APPENDIX B REVIEW OF OPERATIONAL NOISE CRITERIA

APPENDIX C VIBRATION LITERATURE REVIEW

APPENDIX D VIBRATION PREDICTION METHODS

APPENDIX E EXISTING NOISE ENVIRONMENT

APPENDIX F EXISTING VIBRATION ENVIRONMENT

APPENDIX G CONSTRUCTION NOISE CONTOURS

APPENDIX H CONSTRUCTION VIBRATION CONTOURS

APPENDIX I OPERATIONAL VIBRATION CONTOURS

APPENDIX J DRAFT CONSTRUCTION NOISE AND VIBRATION MANAGEMENT PLAN (CNVMP)

APPENDIX K CONSTRUCTION VIBRATION SOURCE REGRESSION CURVES

APPENDIX L REFERENCES

Technical Report to support Assessment of Environmental Effects (City Rail Link Notice of Requirement): Noise and Vibration Assessment



1. GLOSSARY OF TERMS

Term / Acronym Meaning

AEE Assessment of Environmental Effects

Ambient The ambient noise or vibration level is the level measured in the absence of the subject noise or vibration source i.e. before the CRL. Ambient levels are measured to determine the situation prior to the addition of a new noise source.

AT Auckland Transport

BPO Best Practicable Option

CDR Concept Design Report

CH Chainage. Distance in metres along the proposed alignment from Britomart Station towards the North Auckland Line connection

CNVMP Construction noise and vibration management plan. CNVMP is part of the EMP

CRL City Rail Link

dB Decibel - Unit. Used to express noise and vibration levels.

Expressed as a logarithmic ratio of noise pressure or vibration velocity

relative to a reference value i.e. dB = 20 x log(X/Xref), where Xref =20 Pa for noise and 1 nm/s for vibration.

EMP Environmental management plan

EMU Electric Multiple Unit

EPBM Earth pressure balance capable tunnel boring machine. Refer also TBM.

Frequency The number of pressure fluctuation cycles per second of a noise wave. Measured in units of Hertz (Hz).

FTA Federal Transit Administration. The agency within the United States Department of Transportation that provides financial and technical assistance to public transit systems. The FTA General Method has been adopted for the assessment of operation vibration and reradiated noise (refer to Appendix D of this document).

GIS Ground Information Survey - Auckland Council's mapping and property information service

Hertz (Hz) Hertz is the unit of frequency. One hertz is one cycle per second. One thousand hertz (1000 cycles per second) is a kilohertz (kHz).

LAeq (T) The equivalent continuous (time-averaged) A-weighted noise level. This is commonly referred to as the average noise level. The suffix "T" represents the time period to which the noise level relates, e.g. (8 h) would represent a period of 8 hours, (15 min) would represent a period of 15 minutes and (2200-0700) would represent a measurement time between 10 pm and 7 am.

LAFmax The A-weighted maximum noise level. The highest noise level which occurs during the measurement period. F = Fast weighting.

LA10 (T) The A-weighted noise level equalled or exceeded for 10% of the measurement period. This is commonly referred to as the average maximum noise level. The suffix "T" represents the time period to which the noise level relates, e.g. (8 h) would represent a period of 8 hours, (15 min) would represent a period of 15 minutes and (2200-0700) would represent a measurement time between 10 pm and 7 am.




Term / Acronym Meaning

LA90 (T) The A-weighted noise level equalled or exceeded for 90% of the measurement period. This is commonly referred to as the background noise level. The suffix "T" represents the time period to which the noise level relates, e.g. (8 h) would represent a period of 8 hours, (15 min) would represent a period of 15 minutes and (2200-0700) would represent a measurement time between 10 pm and 7 am.

MDA Marshall Day Acoustics

NAL North Auckland Line The existing railway line operating between Newmarket junction via Waitakere to Otiria

NoR Notice of Requirement

PPV Peak Particle Velocity. Peak Particle Velocity (PPV) is the measure of the vibration amplitude, zero to maximum. Used for building structural damage assessment.

Principal Adviser The principal adviser to Auckland Transport for this Project is Aurecon Group

Project Criteria The noise and vibration performance standards, both national and international that are recommended for use in the Project. There are four sub-categories of Project Criteria: Construction Noise, Construction Vibration, Operation Noise and Operation Vibration. Refer Section 6.

Reradiated Noise Noise that is radiated into a room through the vibration of its walls, ceiling and floor. Ground-borne vibration enters a building structure and becomes reradiated noise in each room, if the level is sufficient to be audible.

Road Header A type of tunnel excavating equipment consisting of a boom-mounted cutting head, a conveyor and a crawler travelling track.

Sound Insulation Sound insulation refers to the ability of a material, or building element to reduce sound travelling through it.

Sound Pressure Level (Lp)

A logarithmic ratio of a noise pressure measured at distance, relative to the threshold of hearing (20 Pa RMS) and expressed in decibels.

Sensitive Receivers Receivers (usually building occupants) whose amenity needs to be considered with regards to noise and/or vibration effects; including but not limited to dwellings, hotels, educational facilities, hospitals, places of worship, laboratories, studios, theatres and auditoria.

Special Audible Characteristics

Distinctive characteristics of a noise which are likely to subjectively cause adverse community response at lower levels than a noise without such characteristics. Examples are tonality (e.g. a hum or a whine) and impulsiveness (e.g. bangs or thumps).

Strata (designation) Designation of land layer between the ground surface and the sub-strata designation. This starts at a nominated distance below the surface and extends down to meet the sub-strata designation (the tunnel envelope)

Sub-strata (designation)

Designation of land starting below the strata designation to the centre of the earth (provides for the rail tunnels)

Surface (designation)

Designation of the ground surface (including air space above the land below to the centre of the earth).

TBM Tunnel Boring Machine. A machine designed and used for excavating tunnels with a circular cross-section. Also known as a mole. For CRL, a particular type of TBM is proposed, refer EPBM.




2. EXECUTIVE SUMMARY

This technical expert report provides an independent assessment of the effects associated with the proposed City Rail Link (CRL) from a noise and vibration perspective. The assessment identifies and quantifies issues associated with the construction and operation phases of the CRL, and recommends mitigation options to control the effects. An assessment of the existing noise and vibration environment has been undertaken at key positions along the route.

The construction noise assessment reviews typical machinery and timeframes, predicts the construction noise levels and assesses them in terms of compliance with recommended Project Criteria. Significant effects are predicted from works during the night-time period. However with the implementation of recommended mitigation and the implementation of the Construction Noise and Vibration Management Plan (CNVMP), construction noise effects can be appropriately controlled.

The effects of construction vibration have been quantified by identifying the primary vibration sources. Emission radii which comply with the Project Vibration Criteria have been calculated. GIS based construction contours have been produced to inform the Project Structural Engineering and Built Heritage Experts of buildings at risk of damage. There is potential for effects on some buildings and building occupants. However it is considered that, with the implementation of the CNVMP, the effects of construction vibration on buildings and building occupants can be adequately managed.

Operational noise has been assessed against Project Criteria. The primary noise effect is expected to be from ventilation stacks at each station. With appropriate design these effects can be mitigated.

The primary operation vibration effect is reradiated noise causing disturbance of building occupants. A number of sensitive receivers have been identified and mitigation options have been proposed to reduce the effects.

It should be recognised that the CRL would be of regional and potentially national significance and its noise and vibration effects would be no greater than that of many major roads in the area.

Where recommended mitigation measures are implemented, it is predicted that the noise and vibration effects of the CRL construction and operation can be managed to an acceptable level.




3. PROJECT DESCRIPTION

The City Rail Link (CRL) is a 3.4km underground passenger railway (including two tracks and three underground stations) running between Britomart Station and the North Auckland Line (NAL) in the vicinity of the existing Mount Eden Station. The CRL also requires 850m of modifications within the NAL. For ease of reference in this report, the stations included in the CRL NoR have been temporarily named Aotea Station, Karangahape Station and Newton Station. The stations will be formally named in the future. A fuller description of the CRL is provided in the Assessment of Environmental Effects (AEE) which supports the Notices of Requirement (NoR).

This technical expert report has been developed by Marshall Day Acoustics Limited (MDA) to provide an independent assessment of the effects associated with the proposed CRL from a noise and vibration perspective.

This City Rail Link: Noise and Vibration Assessment is an appendix of the AEE which supports the NoR to be served by Auckland Transport on Auckland Council to designate the CRL for future construction, operation and maintenance. The NoR covers ground surface (surface designation), strata designation (designation of land layer between the ground surface and the sub-strata designation) and sub strata designation (designation of land starting below the strata designation to the centre of the earth-provides for the rail tunnels) within the Auckland City District Plan, both Isthmus and Central Area Sections.

MDA confirms that the content of this report has been written with reference to the Key Project Parameters set out in the Concept Design Report (CDR)1.

4. TECHNICAL ASSESSMENT METHODOLOGY

4.1 Noise

The methodology for assessing the effects of construction and operational noise from the CRL has been divided into ten general steps:

Review the CDR and other documentation provided by AT and its Principal Advisor (Aurecon) to establish an understanding of CRL, and identification of aspects relating to noise for the NoR

Walk the route and undertake visits to certain locations, with AT and other technical experts, to observe, identify and discuss matters relating to the CRL

Identify receivers along the route which may be affected by construction and/or operation noise, and select a representative number of sites for ambient noise measurement

Establish, through noise measurement at these selected sites the existing ambient noise environment (March-June 2012) for sensitive receivers that may in future be affected by construction and/or operational noise from the CRL

1 Concept Design Report: Assessment of Environmental Effects: Volume 3 Technical Reports Appendix 13




Review performance standards currently employed by the territorial authorities with jurisdiction in the CRL area (Auckland Council) in terms of whether they provide appropriate guidelines, and other relevant international standards and guidelines, to develop Project Noise Criteria for the construction and operation phases

Identify those construction and operational activities with the potential to generate noise levels approaching or exceeding the relevant Project Noise Criteria based on the designation footprint and the indicative alignment of the rail tunnels within it, indication construction methodology provided in the CDR, likely rail corridor operations and ancillary support services

Analyse measured and obtained equipment data for baseline assessment purposes

Calculate noise propagation between sources and sensitive receivers and determine whether the predicted noise levels meet the Project Noise Criteria

Assess the noise effects of the CRL for sensitive receivers in the vicinity

Consider current best practicable option (BPO) noise management and mitigation measures, including a Construction Noise and Vibration Management Plan (CNVMP) as part of the CRLs Environmental Management Plan (EMP)

4.2 Vibration

The general methodology for assessing the vibration effects of the CRL has been divided into ten general steps:

Review of the CDR and other documentation provided by AT and its Principal Advisor (Aurecon) to establish an understanding of the CRL, and identification of aspects relating to vibration for the NoR

Walk the route and undertake visits to certain locations, with AT and other experts, to observe, identify and discuss matters relating to the CRL. The vibration assessment is particularly relevant to the Structural Engineering and Built Heritage technical experts, and there has been a particular focus on information sharing between these experts

Attend workshops and meetings with AT, the Principal Advisor and other technical experts to evaluate station options and discuss vibration effects

Review a range of international vibration standards and prediction methodologies to establish a suitable vibration assessment methodology, and Project Vibration Criteria for the construction and operation phases

Establish, through vibration measurements on building structures, the current ambient vibration conditions for sensitive receivers in representative locations

Identify those CRL construction activities likely to generate significant vibration levels, and source data for these activities through previous MDA measurements, and reference literature

Analyse the collected vibration data and using prediction models (incorporating distance and ground attenuation effects), develop contour maps relating to the Project Criteria along the route for both the construction and operation phases. These risk contours are




to be used to assess building damage risk, public complaint risk, and develop mitigation strategies.

Identify key receivers along the route whose building uses are particularly sensitive to vibration or reradiated noise (i.e. auditoria, studios etc.)

Review the catalogue of at-risk building structures along the route contained in the Structural Engineer Report2

Develop best practicable option (BPO) vibration management and mitigation measures, including a CNVMP as part of the CRLs EMP

5. EXISTING ENVIRONMENT

5.1 Existing Noise Environment

5.1.1 Noise Level Surveys

This section provides a summary of the noise level surveys undertaken for CRL over the period March to June 2012. The surveys are intended to provide an understanding of the ambient noise levels in the community adjacent to the CRL prior to construction and operation of CRL. It enables the assessment of noise effects by providing a base level with which predicted construction and future operation noise levels can be compared.

Ten sites were identified as being representative of the existing noise environment at relevant sensitive receiver locations.

DFS Galleria: Representative of residential buildings along lower Albert Street due to the proximity of the designation footprint. The DFS Galleria is housed in a historically significant building. The logger was located on the third floor rooftop of the building, overlooking lower Albert Street. This location enables external noise levels to be measured at a representative height and is similar to locations of noise exposure for other buildings along this part of the alignment

Sky City Grand Hotel: Representative of noise levels along Albert Street and near Aotea Station. A noise logger was located on the walkway roof covering the footpath outside the Sky City Grand Hotel. It should be noted that daytime construction works were taking place at 120 Albert Street throughout the measurements. Nevertheless measured noise levels are consistent with inner city noise exposure and are therefore considered relevant

Aotea Centre: The Aotea Centre is in close proximity of the CRL designation footprint. It houses the ASB Theatre which as a performance venue it is sensitive to noise

The Beresford (22 Beresford Square): Representative of noise levels near the Karangahape Station. An apartment building adjacent to the proposed Karangahape Station and construction worksite. It is considered representative of residential buildings in the area

Mercury Theatre: Representative of noise levels near the Karangahape Station. The Mercury Theatre is also a historically significant building. A noise logger was located on

2 Structural Engineer Report; Assessment of Environmental Effects: Volume 3 Technical Reports: Appendix 10.




the front veranda of the Mercury Theatre at 9 Mercury Lane. The logger was approximately 1m from the building faade

23 Dondunald Street: A residential receiver adjacent to the primary entrance to Newton Station. Access for the noise survey was not obtained

French Caf: Representative of the upper Symonds Street area near Newton Station. A noise logger was located on the front veranda of the French Caf at 210 Symonds Street. The logger was approximately 1m from the building faade

1 Akiraho Street: An apartment building overlooking the current Mount Eden Rail Station and in proximity to the connection of the CRL with the NAL and the main CRL construction worksite. Noise levels measured at this site are representative of noise exposure for other noise sensitive receivers located in proximity to the CRL along the existing NAL rail line

10 Ruru Street: An apartment building located directly above a cut-and-cover section of the route adjacent to the NAL connections and tunnel portals

27 Brentwood Avenue: A residential building in close proximity to the NAL connection. Noise levels measured at this site are representative of noise exposure for other noise sensitive receivers located in proximity to the CRL designation footprint areas along the existing NAL rail line

5.1.2 Noise Level Survey Results

Measurements at 23 Dondunald Street were not possible as access to suitable premises was not obtained.

The results of these nine completed noise level surveys (refer Appendix E) show a high ambient and background noise environment. The locations with the lowest night-time noise exposure are at Akiraho Street, Ruru Street and the French Caf (Newton Station). This is expected, based on their more suburban location. Inner city areas are subject to higher night-time background noise levels. On the weekends, the night-time background noise level along Albert Street is considerably higher at 60 74 dB LA90. The noise level did not drop below 60 dB LA90 at any time at this location. Table 5.1.2 below summarises the results for each of the nine sites.

Table 5.1.2: Existing Noise Environment Summaries

Location Time

Period

Measured Noise Levels

Commentary

dB LAeq dB LA90

DFS Galleria Day 59-72 55-64 The noise environment at this site is elevated during both the day and night-time periods, with background noise levels of 53 64 dB LA90. This is considered to be typical of a metropolitan inner city area, where noise levels are high and controlled predominantly by city road traffic, with contributions from other sources, such as business activity, sirens and alarms.

Night 54-68 53-64




Location Time

Period


Commentary

dB LAeq dB LA90

Sky City Grand Hotel

Day 64-80 62-76 The noise environment at this site is elevated during both the day and night-time periods, with background noise levels of 60-74 dB LA90. This is considered a very high noise level, but typical of a metropolitan inner city area. Background noise levels are also higher on weekends note that the area contains a large number of entertainment facilities.

Night 61-77 60-74

ASB Theatre - Aotea Centre (Inside) (Outside)

Day 29 26 A sound level meter was located on the ground floor of

the ASB theatre in close proximity to the stage. A

corresponding external measurement was taken at rear

faade of the theatre, in a carpark adjacent to Mayoral

Drive. The external measured levels are considered a

typical daytime noise level for a location near a busy

urban road, such as Mayoral Drive.

Day 57 54

The Beresford Day 54-67 50-58 The noise environment at this site is lower than at some

other inner city locations, due to its distance from local

city roads. However, the state highway network is in

reasonable proximity, and does impact to a degree on

the measured noise levels. The background noise levels

of 44 58 dB LA90 are reasonably low for the

metropolitan area. These noise levels are considered

typical of those expected to be experienced on the city

fringe, at distance from local city roads and other noise

sources.

Night 48-64 44-56

Mercury Theatre

Day 60-77 53-66 The noise environment at this site is elevated during both the day and night-time periods, with background noise levels of 46 66 dB LA90. This is considered typical of a metropolitan inner city area, where noise levels are controlled predominantly by city road traffic, with some contributions from other sources. Although this site is more affected by noise from the Central Motorway Junction than the Karangahape Station environs, it is still considered typical of the area.

Night 55-80 46-66

The French Caf

Day 65-81 51-70 The noise environment at this site is elevated during both the day and night-time periods, with reasonably variable background noise levels of 41 70 dB LA90. The noise levels are particularly high during the day, where the area contains a major route into and out of the city centre for road traffic. The night-time noise levels are slightly lower and are more typical of activities associated with commercial operations in the mixed use zone.

Night 54-75 41-64

1 Akiraho Street

Day 51-70 40-55 The noise environment at this site is lower than at other

locations, due to its distance from local roads. However,

the NAL is adjacent to the measurement location, and

does impact the measured noise levels, particularly




Location Time

Period


Commentary

dB LAeq dB LA90

Night 43-70 35-51 during the day. The background noise levels of 35 55

dB LA90 are low. These noise levels are considered typical

of those expected to be experienced by receivers along

the length of the NAL near the CRL designation footprint.

10 Ruru Street Day 50-71 44-55 The noise logger only operated for 11 hours at this

location due to battery longevity. The measured period

shows reasonably low background noise levels of 42 55

dB LA90, consistent with the sites distance from local

roads.

Night 43-53 42-44

27 Brentwood Avenue

Day 40-61 40-53 The noise environment at this site is lower than at other

locations, due to its distance from local roads. However,

the NAL is adjacent to the measurement location, and

does impact the measured noise levels, particularly

during the day. The background noise levels of 40 53

dB LA90 are low. These noise levels are considered typical

of those expected to be experienced by receivers along

this length of the CRL by the NAL.

5.2 Existing Vibration Environment

5.2.1 Vibration Level Surveys

This section provides a summary of ambient vibration surveys undertaken for CRL over the period March to June 2012. The results are intended to provide an understanding of the ambient vibration levels in the community adjacent to the CRL, prior to construction and operation of CRL.

Twelve sites were identified as being representative of the existing vibration environment at relevant sensitive receiver locations. The majority of locations were the same as for the ambient noise surveys (Section 5.1). However, noise surveys required an outdoor location (i.e. balcony) whereas vibration surveys did not, so some vibration locations differed to those selected for noise.

Quay West Suites: Representative of residential buildings on lower Albert Street. The vibration logger was located on the fifth floor of this large residential building and hotel

Sky City Grand Hotel: Representative of vibration levels along Albert Street and near Aotea Station. The vibration logger was located on the ground floor adjacent to Albert Street. It should be noted that daytime construction works were taking place at 120 Albert Street throughout the measurements. Nevertheless measured vibration levels are consistent with inner city vibration levels

Aotea Centre The Aotea Centre is in close proximity to the CRL designation footprint. It houses the ASB theatre which, as a key Auckland performance venue, is sensitive to vibration. The vibration logger was located in the front row of stalls adjacent to the stage




Rendezvous Hotel: Representative of residential/hotel receivers on Vincent Street. The vibration logger was located on the second floor adjacent to Vincent Street (lowest residential floor)

The Beresford (22 Beresford Square): Representative of residential receivers in the Karangahape Road area. The vibration logger was located on the fifth floor balcony. The fifth floor is the buildings first residential floor

George Court Apartments: Representative of residential and hotel buildings on Vincent Street. The vibration logger was located on the second floor

Citt Apartments: Representative of the upper Symonds Street area near Newton Station. The vibration logger was located on the ground floor of the building at the Symonds Street faade

Roundhead Studio: A sensitive receiver and heritage building above the proposed Newton Station and adjacent to the secondary construction/ventilation shaft. Access for the vibration survey was not obtained

23 Dondunald Street: A residential receiver adjacent to the primary entrance to Newton Station. Access for the vibration survey was not obtained

TV 3 Building: A vibration-sensitive environment housing a TV studio. The logger was located in the main broadcast studio

10 Flower Street: A residential receiver. The vibration logger was located on the balcony of a first floor apartment

27 Brentwood Avenue: A residential building in close proximity to the NAL connection. Vibration levels measured at this site are representative of vibration exposure for other vibration sensitive receivers located in proximity to the CRL designation footprint areas along the existing NAL rail line

5.2.2 Vibration Level Survey Results

Measured data and details of the ten completed vibration level surveys have been plotted and summarised in survey sheets attached in Appendix F. Measurements at two locations were not possible, as access to the premises were not obtained.

The mean peak particle velocity (PPV) can be considered representative of the typical vibration levels at each site. Note that overall, the mean PPV values did not exceed the perception threshold (0.3 mm/s PPV) at any site. Table 5.2.2 below summarises the results for each site.

Table 5.2.2: Ambient vibration measurement summary

Location Vibration Levels Commentary

Max PPV

(mm/s)

Mean PPV

(mm/s)

Quay West Suites

0.4 0.2 This is considered typical for a residential building in a

metropolitan inner city area. The mean PPV was below the

threshold of human perception for residents.




Location Vibration Levels Commentary

Max PPV

(mm/s)

Mean PPV

(mm/s)

Sky City Grand Hotel

0.8 0.1 The vibration measurements at this site show reasonably high

activity levels during the daytime and lower levels during the

night-time. This correlates with more activity, including

construction and greater traffic flows, taking place during the

daytime. Overall, the mean PPV is below the threshold of

human perception for occupants.

ASB Theatre - Aotea Centre

0.1 0.1 A short-term measurement was only possible in this location due to theatre scheduling, however this was acceptable due to the consistent vibration level. The level was extremely low inside the ASB theatre, around the limit of sensitivity of the equipment.

Rendezvous Hotel

0.3 0.1 The vibration environment at this site is low, with the mean PPV below the threshold of human perception for residences.

The Beresford 0.2 0.1 The vibration environment at this site is low, with the mean PPV below the threshold of human perception for residences. This is considered typical for a residential building on the city fringe.

George Court Apartments

0.6 0.1 The vibration measurements at this site show reasonably high activity levels during the daytime and lower levels during the night-time. This correlates with more activity, including greater internal movements, taking place during the daytime. Overall, the mean PPV is below the threshold of human perception for residences.

Citt Apartments

0.6 0.1 The vibration environment at this site is low, with slightly higher vibration levels during the day, correlating with greater traffic on Symonds St. The mean PPV is below the threshold of human perception for residences. This is considered typical for a residential building in the mixed use zone.

TV 3 Building 0.9 0.1 In general, the vibration environment at this site is low, with short periods of elevated vibration levels. The Max PPV event was not consistent with the rest of the period, so this was likely due to local activity in the studio area.

10 Flower Street

2.5 0.2 The vibration environment at this site is highly variable, with elevated vibration levels during the daytime exceeding the threshold of human perception at times. There are lower levels generally at night-time. This is consistent with diurnal activities of the occupants, and is unlikely to represent the ambient vibration environment. Overall, the mean PPV is below the threshold of human perception for a residence. Occupant activity is the likely cause of high vibration levels during the daytime.

27 Brentwood Avenue

1.5 0.1 Recorded vibration levels show high activity levels during the daytime and lower levels during the night-time. The mean PPV was 0.14 mm/s which is below the threshold of human perception of 0.3 mm/s PPV for a residential receiver.




6. NOISE AND VIBRATION PERFORMANCE STANDARDS

6.1 Literature review

To ensure the most relevant noise and vibration performance criteria are chosen for the CRL, a review of standards and other literature (e.g. case studies, governmental policies, academic papers etc.) has been undertaken.

The literature reviews for noise and vibration are summarised in Appendices 3, 4, 6, 7 attached. The most relevant to the CRL is the Resource Management Act (RMA), refer Section 6.1.1 below. The proposed Project Criteria are outlined in Sections 6.2 and 6.3 below.

6.1.1 Resource Management Act

Under the provisions of the Resource Management Act (RMA) there is a duty to adopt the best practicable option to ensure that the noise from any development does not exceed a reasonable level. Note that the definition of noise in the RMA includes vibration.

Specifically, Sections 16 and 17 reference noise effects as follows:

Section 16 states that every occupier of land (including any coastal marine area), and every person carrying out an activity, shall adopt the best practicable option to ensure that the emission of noise from that land or water does not exceed a reasonable level

Section 17 states that every person has a duty to avoid, remedy, or mitigate any adverse effect on the environment arising from an activity, whether or not the activity is in accordance with a rule in a plan, a resource consent or relevant sections of the RMA

6.2 Project Criteria - Construction Phase

6.2.1 Construction Noise

A review of relevant construction noise standards and other performance criteria for the assessment of construction noise effects is included as Appendix A. This includes a review of construction noise limits adopted for a sample of other relevant projects in the Auckland area and United Kingdom (Auckland Electrification Project, Waterview Connection, and Crossrail UK). A summary of the review and recommended Project Criteria is contained below.

Under the provisions of the Resource Management Act (Sections 16 and 17) there is a duty to adopt the best practicable option to ensure that noise does not exceed a reasonable level, and that any adverse effects shall be avoided, remedied or mitigated. This report supports the AEE for the NoR to designate land for the CRL, and therefore compliance with the District Plan noise rules would not apply to the works covered under the CRL designation. Rather, District Plan noise rules provide guidance as to acceptable standards for compliance. It is considered that compliance with the recommended Project Noise Criteria in accordance with the provisions of the Construction Noise Standard (NZS 6803:1999), including implementation of an approved CNVMP as part of the wider EMP, would constitute the adoption of the best practicable option.

The Construction Noise Standard NZS 6803: 1999 provides for relaxed limits during normal working hours to enable construction activity to take place. However, it makes no allowance for noisy construction work during Sundays or night-time periods. We note that the Auckland City District Plan (Central Area Section) recognises the nature of the high existing




noise environment and specifies higher noise limits for these periods. Note that at night, the primary acoustic objective is to ensure that any noise activities do not give rise to sleep disturbance for occupants of dwellings. For this reason, Auckland City District Plan (Isthmus and Central Area Sections) have set internal noise limits for habitable spaces in new dwellings due to external noise sources (such as traffic or commercial activities).

Aligned with this, MDA considers that construction activities would be deemed acceptable if the noise generated in the bedrooms of dwellings did not exceed 35 dB LAeq. However, we consider in special cases that this limit could be relaxed by 5 decibels where a specific scheduled construction activity would only occur for 1 period of up to 2 consecutive nights in any 10 days. Similarly, in special cases the daytime limit could also be relaxed where a specific scheduled construction activity would only occur for 1 period of up to 2 consecutive weeks in any 2 months. Any such special case would still require the use of noise management techniques as part of best practicable option to ensure that noise contributions from construction activity are reduced.

Table 6.2.1 below is reproduced from Table A8 of Appendix A. It presents recommended Project Criteria for construction noise. The criteria would be implemented in conjunction with a Construction Noise and Vibration Management Plan (CNVMP) as part of the wider EMP, of which a proposed draft is included in Appendix J.

Table 6.2.1: Project Criteria Construction Noise

Description All days (dB LAeq)1

Day time2

(0700 to 2300) Night-time

3

(2300 to 0700)

Commercial and industrial buildings 75 80

Noise sensitive activity (e.g. dwelling) 75 604

Notes: 1. Construction noise should be measured and assessed in accordance with the provisions of NZS

6803:1999 2. Noise limit may be relaxed by 5 decibels for 1 period of up to 2 consecutive weeks in any 2 months 3. Noise limit may be relaxed by 5 decibels for 1 period of up to 2 consecutive nights in any 10 days 4. Or 35 dB LAeq measured inside a bedroom

6.2.2 Construction Vibration

Two types of construction vibration effects are considered:

Vibration damage to buildings

Human response to construction vibration

The risk of building damage exists primarily during the construction phase because the machinery involved (e.g. vibratory rollers) deliver more energy into the ground (and therefore into buildings) than a train, and are often in closer proximity to receivers.

Effects relating to human response (e.g. annoyance, sleep disturbance) can generally be avoided and/or mitigated through the effective implementation of the CNVMP. Also, the construction period will have a defined timeframe (indicatively at this stage as 5-6 years), so receivers understand when the effects will cease. Moreover, the most common concern of




occupants during construction is damage to their building, and this is addressed by applying the building damage criteria.

Vibration Building Damage: DIN 4150-3:1999

There are no New Zealand standards that address construction vibration. As discussed above, the primary concern during the construction phase is damage to buildings.

The Standard most commonly used in New Zealand to address building damage risk from ground-borne vibration is German Standard DIN 4150-3:1999 Structural Vibration - Part 3: Effects of Vibration on Structures. It (and the preceding 1986 version of the same Standard) is referenced in the Auckland and Waitakere City District Plans, the NZ Transport Agency Environmental Plan and the National Environmental Standard for Electricity Transmission Activities. It has been adopted for major infrastructure projects throughout New Zealand such as Waterview Connection (road and tunnel), MacKays to Peka Peka (road), Vic Park Tunnel (road and tunnel) and the NoR for Marsden Point Rail Link (rail).

It should be noted that DIN 4150-3:1999 is a conservative standard. Its criteria are designed to avoid superficial damage to buildings and are well below the levels at which damage to building foundations would occur (Siskind et al., 1980).

Tables 1 and 3 of the DIN 4150-3:1999 Standard are adopted as Project Criteria, and are summarised in Table 6.2.2.1 below. The standard states Experience has shown that if these values are complied with, damage that reduces the serviceability of the building will not occur.

Table 6.2.2.1: Project Criteria Construction Vibration (Building Damage)

Type of Structure

Short-term vibration Long-term vibration1

PPV at the foundation at a frequency of PPV at horizontal plane of highest

floor (mm/s)

PPV at horizontal plane of highest floor

(mm/s) 1 - 10Hz (mm/s)

1 - 50 Hz (mm/s)

50 - 100 Hz (mm/s)

Commercial/ Industrial

20 20 40 40 50 40 10

Residential/ School

5 5 15 15 20 15 5

Historic or sensitive structures

3 3 8 8 10 8 2.5

Note: 1. Standard defines short-term vibration as vibration which does not occur often enough to cause

structural fatigue and which does not produce resonance in the structure being evaluated. Long-term vibration defined as all other vibration types not covered by the short-term vibration definition.

The majority of the CRLs construction vibration activities would be classed as long-term. Note this term defines a property of the vibration signal, and is not related to construction time-frame.




Vibration Human Response: BS 5228-2:2009

As noted previously, the risk of building damage is considered to be the primary effect during the construction phase of the CRL. However Appendix B.2 of British Standard BS 5228-2:2009 provides supplementary guidance relating to human expectations and response to construction vibration. The criteria are given in Table 6.2.2.2 below.

Table 6.2.2.2: Guidance for human response to construction vibration in BS 5228-2:2009, Annex B

Vibration level (PPV) Effect

0.14 mm/s Vibration might be just perceptible in the most sensitive situations for most vibration frequencies associated with construction. At lower frequencies, people are less sensitive to vibration.

0.3 mm/s Vibration might be just perceptible in residential environments

1.0 mm/s It is likely that vibration of this level in residential environments will cause complaint, but can be tolerated if prior warning and explanation has been given to residents.

10 mm/s Vibration is likely to be intolerable for any more than a very brief exposure to this level.

Note that according to the Standard these values relate to effects on residences, however they can reasonably be applied to offices, with 1 mm/s being acceptable provided notification has been given.

Comparing these values with the DIN 4150-3:1999 criteria, it can be seen that people are likely to complain at vibration levels significantly below those which may cause superficial building damage (such as cracking in paint or plasterwork). Additionally, people are generally more sensitive to vibration at frequencies higher than those which cause building damage. Construction activities generate vibration at a wide range of frequencies, and peoples sensitivity to the higher frequencies in this range exacerbates their perception of the potential for building damage. It is anticipated that construction activities which cause concern, but not building damage, will be managed by the CNVMP, in particular through community liaison and education.

It is noted that the BS 5228-2:2009 Standard does not address the effects of reradiated noise i.e. vibration energy in the building structure that manifests itself as a 'rattle or hum' and is heard rather than felt. It is often difficult for a listener to distinguish this effect from felt vibration, and complaints of vibration can be made when the cause of disturbance is in fact reradiated noise.

This effect varies considerably from structure to structure due to complexities in the connection of building elements and variance in building materials etc. It is anticipated that for the construction phase, this effect would be handled on a case-by-case basis through the complaint management procedures in the CNVMP.

For the operational phase, reradiated noise is considered and addressed as a separate effect to vibration. Refer Project Criteria presented in Table 6.2.1.




Vibration Damage to Services: DIN 4150-3:1999

The DIN 4150-3:1999 standard also contains criteria for buried pipe work (Table 2 of the Standard). The criteria vary depending on the pipe material, and range from 50 mm/s to 100 mm/s PPV. The management of damage risk to pipes and other underground services should be undertaken on a case-by-case basis through the CNVMP.

6.3 Project Criteria - Operational Phase

6.3.1 Operational Noise

A review of relevant noise standards for this assessment is contained as Appendix B. A summary of the review and recommended Project Criteria is reproduced below.

NAL has a Kiwi Rail designation for rail purposes. As such, the District Plan noise rules do not apply for the control of noise emissions within this designation. CRL above-ground rail movements will be within the existing NAL designation, and as such, the conditions of the NAL designation apply. Therefore CRL works to be undertaken within the NAL designation footprint will not be covered by the CRL NoR.

CRL footprint areas are identified adjacent to the NAL designation as a result of new or realigned tracks and other rail infrastructure. It is appropriate to assess the indicative change in noise level due to, for example, tracks being moved closer to a noise sensitive receiver. A change in noise level of 1-2 decibels is generally considered to be indiscernible, while 3-4 decibels is just noticeable. On this basis, the noise effect from a change in noise level of less than 3 decibels is considered to be negligible.

Note that the KiwiRail Reverse Sensitivity Guidelines can be used as a guide for new rail infrastructure developments for control of noise emissions, as well as providing methods to control reverse sensitivity effects arising from incompatible developments nearby. Further discussion is given in Appendix C.

The District Plan noise rules are considered appropriate for assessment of mechanical plant and ancillary infrastructure servicing the underground rail sections of the CRL. Consequently, the Project Criteria largely mirror the District Plan criteria. However, the latest (2008) versions of NZS 6801 and NZS 6802 now recognise the equivalent continuous sound level (LAeq) as the noise index that best represents the community response to noise, as opposed to the LA10 noise index used in previous standards (note Auckland Council is likely to adopt the LAeq noise index during the next review of the District Plan). The recommended Project Criteria for operational noise is presented in Table 6.3.1 below (reproduced from Table B4 of Appendix B).

Table 6.3.1: Project Criteria Operational Noise (excluding rail movements)

Location Period dB LAeq dB LAFmax

Auckland Central Area 7.00am to 11:00pm 65

11:00pm to 7:00am 60 70 @ 63 Hz

65 @ 125 Hz

75

Auckland Isthmus Area 7.00am to 10:00pm 60

10:00pm to 7:00am 55 75




6.3.2 Operational Vibration and Reradiated Noise

There are no current New Zealand standards that address human response to vibration or reradiated noise from trains. Furthermore, CRL is the first significant underground rapid transit project undertaken in New Zealand, so there is little precedent in terms of vibration methodology or assessment.

A number of international projects were reviewed to identify the commonly adopted methods and criteria (refer Appendix C). The method that has been adopted for CRL is the United States Federal Transit Administration (FTA) General Assessment Method (refer Appendix D). It has been chosen because it is a comprehensive tool integrating both prediction and assessment methodologies, it is well supported by academic research (Saurenman et.al., 1982), and has been used in many significant rapid transit projects.

The performance standards in the FTA General Assessment Method set out suitable performance standards for vibration and reradiated noise from underground and surface railways. These have been adopted as the CRL operational Vibration Criteria, as summarised in Table 6.3.2 below. The vibration criteria are also expressed as PPV values (unlike in the FTA document). It is noted that the reradiated Noise Criteria for dwellings in Table 6.3.2 match those contained in the Kiwirail Reverse Sensitivity Guidelines (refer Appendix C).

Table 6.3.2: Project Criteria Operation Vibration

Building Type

Vibration Criteria Reradiated Noise Criteria

(dB re: 20 Pa) (dB re: 1 nm/s)

PPV (mm/s)

Commercial and Industrial Buildings

103 0.2 40

Dwellings 100 0.15 35

Auditoria/Theatres 97 0.1 30

TV/Recording Studios 93 0.06 25

A vibration level of 100 dB corresponds to approximately 0.15 mm/s PPV, which is close to the limit of perception (refer Table 6.2.2.2), so effectively the FTA objective for dwellings is imperceptibility. The limit for auditoria/theatres is lower (to ensure there is no disturbance), and the limit for TV/Recording Studios is lower again, most probably to avoid effects on equipment (e.g. camera shake or electrical noise). Note also that these values are an order of magnitude below the most stringent building damage criterion of 2.5 mm/s, so compliance with the limits in Table 6.3.2 indicates that there is no risk of vibration induced building damage from operation of the CRL.




7. ASSESSMENT OF EFFECTS ON THE ENVIRONMENT AND MITIGATION OPTIONS CONSTRUCTION PHASE

7.1 Construction Noise

7.1.1 Key Construction Noise Considerations

The indicative 5 6 year construction programme, including worksites A I, is contained in the CDR. The construction programme is largely dictated by the tunnelling timeline. Exposed above ground works are expected to result in significantly more noise impact compared with tunnelling and enclosed works (e.g. excavation of the two tunnels, construction inside stations and enclosed cut-and-cover sections). With the exception of the NAL connection site, the duration of above ground construction works is anticipated to vary significantly, but be a small proportion of the total programme period at any one location.

This assessment focuses on the following five grouped above ground worksites:

Britomart Station to Aotea Station (Worksites E, F, G and H)

Karangahape Station (Worksite D)

Newton Station (Worksite C)

Connection with the NAL and the main construction site (Worksites A and I)

The construction of CRL will result in noise which will have some impact on occupiers in the vicinity of the required works for a limited period. The following sub-sections identify key construction activities, determine the likely noise levels generated by the activities, predict the resulting noise effects and discuss feasible mitigation measures.

While the indicative construction methodology provides a basis for the assessment of effects, there is the potential that the actual methodology used may differ in some aspects depending on the approach taken by the contractor. However, a prudent assessment has been undertaken for the purposes of this report, and it is expected for the majority of the CRL, that noise emissions will not vary significantly between methodologies where the equipment required for each is likely to be somewhat similar (e.g. using bulldozers or graders for earthworks). For some specific activities, noise levels may vary markedly for different methodologies (e.g. alternative piling techniques). Deviation from the indicative methodology would be addressed in the CNVMP to achieve the best practicable option for mitigation.

7.1.2 Source Data

Table 7.1.2.1 overleaf contains a list of typical noisy machinery items or activities anticipated as part of the CRL construction works. It is not intended to be exhaustive, but form a basis for this assessment. The plant items are paired with reference to noise sources in Annex C and D of BS 5228-1, which is referenced by NZS 6803: 1999.




Table 7.1.2.1: Machinery Items

Item Machinery Item BS 5228 reference Item Noise Level at 10m (dB LAeq)

1 Mobile Crane C4.43 70

2 Diaphragm wall rig D4.101 86

3 Secant piling rig D4.93 89

4 Bentonite / grouting plant D6.9 76

5 Concrete truck C4.18 75

6 Excavator C4.64 75

7 Road truck (idling) C4.8 56

8 Road truck movements C4.7 78

9 Dewatering C2.45 65

10 Front End Loader C2.28 76

11 Grader D3.75 84

12 Vibratory Roller C5.25 75

13 Excavator with Pecker C1.4 76

Table 7.1.2.2 below presents anticipated construction activities', which are combinations of the individual items from Table 7.1.2.1. Cumulative activity noise levels enable simple assessment for comparison with recommended construction noise limits (refer Table 6.2.1) and minimum setback distances.

Table 7.1.2.2: Construction Activities

Activity Construction Activity Machinery Items Activity Noise Level at 10m (dB LAeq)

A D-wall construction 1, 2, 4, 5, 7, 9 87

B Secant piling 1, 3, 4, 5, 7, 9 89

C Excavation 6, 7, 9 75

D Surface works 6, 7, 11, 12 85

E NAL site tunnelling services 4, 6, 7, 10 80

F Truck movements off-site 8 78

G Demolition 7, 13 76

Note that cumulative activity assessment is considered conservative and appropriate for assessing a prudent effects envelope, because it assumes all group items operate continuously and simultaneously for the full assessment period. Furthermore, it assumes that all noise sources are concentrated at one source position, when in practice they may be geographically spread over a site. Therefore in practice, activity levels will likely be lower than those in Table 7.1.2.2.

Multiple activities (e.g. D-Wall construction and Excavation) will often occur simultaneously, however they would be geographically separated. Therefore the construction noise levels within close proximity of the worksite are likely to be dominated by the closest activity, but may increase the level by up to 3 decibels in some cases.




7.1.3 Noise Prediction

Table 7.1.3.1 overleaf summarises the required setback distance from an activity to enable compliance with the most relevant Project Criteria; daytime period at all receiver types, and night-time at residential receivers (refer Table 6.2.1 for full criteria).

Table 7.1.3.1: Setback Distance

Activity Construction Activity Approximate Setback Distance1 (m)

75 dB LAeq2

60 dB LAeq3

A D-wall construction 40 220

B Secant piling 50 300

C Excavation 10 60

D Surface works 30 180

E NAL site tunnelling services 20 110

F Truck movements off-site 15 80

G Demolition 10 60

Notes: 1. Setback distances may be shorter with the inclusion of intermediate building shielding and mitigation 2. Daytime Project Criteria at all receiver types 3. Night-time Project Criteria at residential receivers

Table 7.1.3.2 below summarises the activities considered at each assessment site. Note that provision for 24 hour construction is preferred to provide the maximum flexibility for working in the Central City area, where it may be more practical and the best practical option to undertake works at night.

Table 7.1.3.2: Site Activities

Est. Chainage Construction Site Surface Works Summary Construction Activities

0000 1000 Britomart Station to Aotea Station (Sites: E, F, G, H)

Demolition and site preparation works, staged cut-and-cover tunnel and station construction to minimise road closures, and station construction.

A, B, C, D, F, G

1850 & 2025 Karangahape Station (Site: D)

Demolition and construction of two cut-and-cover station shafts; corner of Beresford St and Pitt St, and corner of Mercury Ln and Cross St.

A, C, F, G

2700 & 2800 Newton Station (Site: C)

Demolition and construction of two cut-and-cover station shafts; corner of Symonds St and New North Rd, and near corner of Dundonald St and Newton Rd.

A, C, F, G

3100 3350 Connection to the NAL and the main construction site (Sites: A, I)

Demolition and site preparation works for NAL connection site, cut-and-cover construction to NAL connection, and tunnelling supports services.

A, B, C, D, E, F, G

Computer modelling of noise generated by one selected construction activity at each site has been undertaken to assess the effects for the determination of appropriate mitigation measures. Modelling enables a comprehensive overall picture of future noise effects to be




produced and has utilised SoundPLAN, an internationally recognised computer noise modelling programme.

In summary, SoundPLAN uses a digital topographical terrain map of the area as its base. Each noise source (refer Table 7.1.2.1) is located in the digital map and the software then calculates noise propagation for multiple directions, allowing for terrain, topography, shielding, and meteorological conditions. The SoundPLAN model uses the calculation algorithms of ISO 9613-2: 1996 Acoustics Attenuation of noise during propagation outdoors Part 2: General method of calculation.

Noise contours plans are presented at 1.5m elevation as well as 3D projections of the contours to show the noise profile on building facades. The most relevant activity for each section has been modelled in SoundPLAN, as follows:

Britomart Station to Aotea Station: Activity B (Secant Piling) at Aotea Station (Worksite E)

Karangahape Station: Activity A (D-wall construction) at Beresford St shaft (Worksite D)

Newton Station: Activity A (D-wall construction) at Dundonald St shaft (Worksite C)

Connection to the NAL and the main construction site: Activity E (NAL site tunnelling services) at tunnelling support site (Worksite A)

7.1.4 Britomart Station to Aotea Station

Activity B (secant piling) is the loudest activity type in Table 7.1.2.2. This activity is proposed for cut-and-cover construction from Britomart to Aotea Station (as well as the connections to the NAL). Within this section, Aotea Station was chosen as the modelling site due to its proximity to a large number of noise sensitive receivers. Noise contours are presented in Figures 1 and 2 of Appendix G.

It can be seen that the immediately adjacent buildings are predicted to be subject to noise levels in excess of the 75 dB LAeq daytime Project Criteria (refer Table 6.2.1). This model does not include mitigation measures such as a site perimeter hoarding, as they are likely to have limited benefit for any receivers except ground floor occupants. However it can also be seen that affected buildings provide intermediate shielding to noise sensitive receivers located beyond, limiting the number of affected receivers. This model is a snapshot-in-time of particularly noisy works at one location. As the works migrate along the worksite from Britomart Station to Aotea Station, the contours will vary depending on the intermediate shielding provided by adjacent buildings, topography and mitigation measures applied.

7.1.5 Karangahape Station and Newton Station

Activity A (D-wall construction) is the loudest activity type at both Karangahape Station and Newton Stations. This activity is proposed for cut-and-cover construction of the station access and ventilation shafts. Beresford St (northern) shaft at Karangahape Station and Dundonald St (northern) shaft at Newton Station were chosen due to their proximity to noise sensitive receivers. With the activity located near the centre of the proposed respective shafts, noise contours are presented in Figures 3 and 5 of Appendix G. 3D projections of the contours are presented in Figures 4 and 6 of Appendix G.

As per Section 7.1.4, it can be seen that the immediately adjacent buildings are predicted to be subject to noise levels in excess of the 75 dB LAeq daytime Project Criteria (refer Table 6.2.1). This model does not include mitigation measures such as a site perimeter hoarding,




as they are likely to have limited benefit for any receivers except ground floor occupants. However it can also be seen that affected buildings provide intermediate shielding to noise sensitive receivers located beyond, limiting the number of affected receivers.

7.1.6 Connection to the NAL and the main Construction Site

Activity E (activities associated with the operation and maintenance of the TBM tunnelling) is proposed only at the NAL end of the CRL and within the main construction worksite. This activity is unique in terms of its 24 hour / 7 day operation, multi-year duration, and location. These activities include conveying and equipment associated with spoil removal, tunnelling ventilation, construction dewatering, tunnel wall panel forming and storage facilities. The proposed construction site is located on a strip of land adjacent to the northern side of the NAL, stretching west from Ruru Street to Porters Avenue. Noise contours are presented for the activity grouped at two arbitrary site locations referred to as eastern scenario and western scenario respectively (the proposed site setup and machinery item locations will not be known until the contractor is appointed). The eastern scenario has the activity centred between Ruru and Ngahura Streets, presented in Figures 7 and 8. The western scenario has the activity centred between Ngahuru Street and Porters Avenue, presented in Figures 9 and 10.

It can be seen for both scenarios that the received noise levels at immediately adjacent buildings are predicted to comply with daytime Project Criteria recommended in Table 6.1.2. The majority of faades that are shown to exceed 60 dB LAeq are not residential / noise sensitive buildings, therefore also comply with the night-time Project Criteria. Identified residential faades exceeding 60 dB LAeq are marked with a red shaded roof. An example that does not comply is at the residential building on the corner of Ruru and Nikau Streets where the activity is located at the eastern end of the site. However with the application of appropriate mitigation and management to control noise emissions (refer Section 7.3 and 7.4), this activity will likely enable compliance with the Project Criteria at all locations. For example, favourable site setup to locate noisy machinery items away from noise sensitive receivers, use of site buildings as intermediate acoustic barriers, avoiding night-time operations of targeted machinery items and selection of low noise equipment.

Other activities may operate simultaneously on the adjacent designated sites (such as cut-and-cover works for the tunnel portal). Therefore depending on the site location, the cumulative construction noise emissions may exceed the Project Criteria. Activity B (secant piling) is the loudest expected within this area of the designation footprint. Refer to Section 7.1.4 for typical noise propagation from this activity. Note that as mentioned above, the levels will vary depending on the shielding provided by intermediate buildings, topography and mitigation measures applied.

7.1.7 Other Construction Activities

Other activities not addressed above are anticipated to have effects similar to, or less than those discussed above. These are addressed briefly below:

Activity C (Excavation): This activity will occur during cut-and-cover construction at ground level. Once the section is covered at ground level and excavation recommences below ground level, the noise levels received are anticipated to drop significantly, depending on ventilation, truck movements and conveying equipment where required




Activity F (Truck movements off-site): Truck movement strategy would form part of the CNVMP and can be managed to control noise effects

Activity G (Demolition): Demolition will be managed through the CNVMP to control noise effects

7.1.8 Assessment of Effects

Construction activities will occur in close proximity to receivers, and during sensitive periods when restricted Project Criteria are recommended. In some instances, noise emissions will potentially exceed the recommended Project Criteria.

For most large scale construction projects, exceedances of their construction noise limits for brief periods are common. Provided these exceedances are temporary and brief, noise levels may not be unreasonable. Measures should be implemented to avoid, remedy and mitigate noise generation as far as is practicable, particularly for exceedances of longer duration or greater magnitude.

The received internal noise level (e.g. in an office or bedroom) will depend on the sound insulation performance of the faade (particularly the glazing) as well as room constants (such as room dimensions and surface finishes). As these factors can vary widely, the construction noise standard (NZS 6803) provides its guidance with respect to external faade levels dependant on internal receiver type. Commentary on typical faade sound level difference for New Zealand dwellings is included in Appendix A, Section A8.

For the purpose of this document, the generalised faade sound insulation performance of buildings is categorised by the type of glazing / ventilation provision as follows:

Sealed glazing 30 decibels level difference (Dw)

Operable windows 25 decibels level difference (Dw)

Open Windows 15 decibels level difference (Dw)

Noise effects matrices presented in Tables 7.1.8.1 and 7.1.8.2 will assist people to estimate the internal noise level received during construction based on the external noise level and faade glazing type. They are indicative for NoR purposes only, as it is recommended that receivers be addressed on a case by case basis (as appropriate) at a detailed design and / or construction stage. The potential risk of noise effects is colour coded as follows:

Green: Acceptable

Orange: Minor

Red: Significant

To use the matrices, follow this three step process:

Estimate the external noise level at a relevant faade from Table 7.1.3.1 or indicative construction noise contours provided in Appendix G

Determine the category of faade glazing sound insulation performance presented on the previous page

Use the relevant lookup Table 7.1.8.1 or 7.1.8.2 to estimate the received internal noise level to identify the potential risk of effects, and examples of effects which may be experienced




Table 7.1.8.1: Daytime in commercial & industrial buildings and habitable rooms in dwellings

External Noise Level (dB LAeq) Estimated Internal Noise Level (dB LAeq)

(refer Appendix G) Sealed glazing (Dw 30 dB)

Operable windows (Dw 25 dB)

Open windows (Dw 15 dB)

90 60 65 75

85 55 60 70

80 50 55 65

75 45 50 60

70 40 45 55

65 35 40 50

60 30 35 45

< 50 dB LAeq Typically acceptable

50 60 dB LAeq Annoyance and reduction in work efficiency

> 60 dB LAeq Difficulty holding a normal conversation and reduction in work efficiency

For commercial and industrial receivers and habitable rooms in dwellings during the day, effects could range from difficulty holding a normal conversation to a reduction in work efficiency. However, the effects from these activities during the daytime period may be controlled with the implementation of an appropriate CNVMP, as part of the wider EMP.

Table 7.1.8.2: Night-time in bedrooms of dwellings

External Noise Level (dB LAeq) Estimated Internal Noise Level (dB LAeq)

(refer Appendix G) Sealed glazing (Dw 30 dB)

Operable windows (Dw 25 dB)

Open windows (Dw 15 dB)

90 60 65 75

85 55 60 70

80 50 55 65

75 45 50 60

70 40 45 55

65 35 40 50

60 30 35 45

< 35 dB LAeq Typically acceptable

35 40 dB LAeq Annoyance and sleep disturbance for some noise sensitive receivers

> 40 dB LAeq Annoyance and sleep disturbance for most noise sensitive receivers

Piling and surface works (activities A, B, C, D and G) are predicted to significantly exceed the night-time Project Criteria at nearby noise sensitive receivers (such as dwellings). For these




receivers, effects could range from annoyance to sleep disturbance. Due to the magnitude of the exceedance, significant adverse effects are predicted at worst effected noise sensitive receiver locations. It is recommended that these activities be undertaken during day and evening periods where practicable, or with agreement of sensitive receivers, they be temporarily relocated for the duration exceeding the Project Criteria. The noise effects from these activities during the daytime period may be controlled with the implementation of an appropriate CNVMP, as part of the wider EMP.

The tunnelling activities and truck movements associated with the main construction site area and connections to the NAL (activities E and F), are predicted to comply with the Project Criteria at the majority of receiver locations. With the application of appropriate noise management and mitigation, the noise effects from these activities are predicted to be acceptable.

7.2 Construction Vibration

7.2.1 Key Construction Vibration Considerations

As discussed in Section 6.2.2, the primary concern of building occupants during the construction phase is likely to be building damage. The key output of this assessment, therefore, is identifying buildings that may be at risk of vibration induced damage from construction machinery. Risk contours have been developed to enable other experts (e.g. Structural Engineering and Built Heritage) to produce registers of at-risk buildings (refer Section 7.2.3).

Development of the risk contours has involved consideration of the following variables:

Highest anticipated construction vibration source levels from collected and referenced data

Distance from source to building which is dependent on tunnel depth and building foundation depth (particularly whether the building has basement levels)

Receiver type categorised according to DIN 4150-3:1999

Adverse human response effects to construction vibration are expected, with levels high enough to impede daily activities or disturb sleep at some receivers (in the case of 24 hour operations such as TBM tunnelling). These effects will be managed through the CNVMP, in particular by communication and liaison strategies.

This assessment is limited to the prediction of vibration levels at building foundations. The potential effects on buildings are guided by the assessment criteria contained in DIN 4150-3:1999, but the responsibility for assessing the building response and structural integrity lies with the Structural Engineering expert, with reference to the risk contours (refer Section 7.2.4).

7.2.2 Source Data

Vibration data for activities have been sourced from historical Marshall Day Acoustics (MDA) measurements, BS 5228-2:2009 and the Cross River Rail Project (refer Appendix L). The most significant vibration-inducing construction activities have been identified as:

Vibratory Roller preparation of road surface, and rail base course preparation in cut-and-cover and surface works sections




Road Header hand-mined tunnel, station and construction shaft excavation

Tunnel Boring Machine (TBM) driven tunnel excavation

Diaphragm Wall Rig D-wall construction for cut-and-cover sections

It is noted that other construction machinery may produce vibration, but these four identified sources are the worst-case within the indicative construction methodology.

Regression analysis of measured data has been undertaken to establish vibration propagation trends. The dataset is representative of generic measurements which vary in terms of machine type/size and ground conditions, so caution is needed in applying these to other sites. A safety factor of 100% has been added to the regression curves (refer Hunt et al., 2010), to ensure conservative estimates until on-site testing can be undertaken to refine the prediction model. Note this was essentially the same method adopted for the Waterview Connection Project. The most common geology for that Project was East Coast Bays Formation (ECBF) - a softish sandstone (depending on its weathered status), which is the same for CRL.

The propagation model used in the assessment and a discussion of geology are attached in Appendix D. The vibration regression curves for the four identified sources are attached in Appendix K.

7.2.3 Construction Contours

Maps of construction contours indicating the vibration risk to buildings of different types are shown in Appendix H. They were produced by the BECA GIS team using emission radii values from MDA and 3D alignment data from Aurecon (Auckland Transport Principal Advisor for CRL). The GIS framework enables flexible and customised assessment of construction vibration

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