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C1 2 Flower Street (MediaWorks) SSCNVMP
C1 2 Flower Street (MediaWorks) SSCNVMP
C1.1 Introduction
This Site Specific Construction Noise and Vibration Management Plan (SSCNVMP) is for the MediaWorks Building at 3 Flower Street. It is required to satisfy CRL designation conditions 35, 39 and 40. As Appendix C1 of the Mt Eden Main Works Construction Noise and Vibration Delivery Work Plan (CNV DWP), this SSCNVMP is a supplementary document that builds on the CNV DWP, and therefore, directly references relevant sections of the CNV DWP to avoid repetition. Together, the CNV DWP and MediaWorks SSCNVMP are consistent with the draft MediaWorks SSCNVMP 1 . It will be implemented for works within 100m and blasting activities within 200m of the MediaWorks Building. The objective of this SSCNVMP is to detail the best practicable option(s) (BPO) to avoid, remedy or mitigate the identified adverse effects on MediaWorks. It contains, or references:
Details of those responsible for implementing this SSCNVMP (CNV DWP Section 3)
MediaWorks noise and vibration sensitive spaces (Section C1.3) The relevant standards (the general requirements in CNV DWP Section 4 and the MediaWorks specific requirements for Studio 1 are summarised in Section C1.2) Predicted construction noise and vibration levels and transfer functions (Section C1.4)
Mitigation and management measures (CNV DWP Section 9) Communication protocol (CNV DWP Section 10)
Monitoring (CNV DWP Section 11 and Section C1.5 specifically for Studio 1) Contingency measures (CNV DWP Section 12.3 and Section C1.6 specifically for Studio 1).
SSCNVMP review process (CNV DWP Section 1.6 and CRL designation condition 40.13) This SSCNVMP has been prepared by Marshall Day Acoustics and forms part of the Construction Environmental Management Plan (CEMP) for the Mt Eden Main Works. It builds on the SSCNVMP previously prepared and implemented for the Mt Eden Enabling Works.
1 Project Agreement in respect of the City Rail Link between Auckland Transport (AT) and MediaWorks Holdings Limited (Mediaworks), reference item 6 and Appendix 1. Page 8 | Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs
C1.2 Construction Noise and Vibration Standards
The relevant construction noise standards are summarised in Table C1.2.1.
Table C1.2.1: Construction Noise –MediaWorks
Condition
31.1
32.2
32.3
35.2
Requirement
General 2
Blasting 3
Blasting 3
Studio 1 4, 5
Limit
75 dB L Aeq
120 dB L Zpeak
133 dB L Zpeak
30 dB L Aeq (5 min) 6 33 dB L Aeq (1 sec)
Assessment location (period)
External façade (all times)
External façade (occupied times)
External façade (unoccupied times)
Studio 1 (Sensitive Times)
The relevant construction vibration standards are summarised in Table C1.2.2.
Table C1.2.2: Construction Vibration –MediaWorks
Condition
32.4
Requirement
Amenity (blasting)
33.1
35.3 Building Damage 8
Studio 1
35.6
35.8 Amenity
Sensitive equipment
Limit
10 mm/s PPV for 95% of events 15 mm/s PPV for 100% of events
Refer DWP Section 5.2.1
0.1 mm/s PPV 9 construction 0.25mm/s PPV demolition only (excluding blasting)
1 mm/s PPV
5–500Hz: 200mg (2 m/s 2 )
Assessment location 7 (period)
Floor of occupied areas.
Building foundations or Top floor
Floor of Studio 1 (Sensitive Times). If compliant in Studio 1, vibration in other studios will be acceptable.
Floor of office areas, meeting rooms and technical suites (occupied times).
Floor supporting sensitive equipment
The operational requirements and constraints provided by MediaWorks for Studio 1 are detailed in CRL designation conditions 35.1 –35.3 and summarised as follows:
Sensitive Times are defined as:
2 Measured and assessed Construction Noise” in accordance with the provisions of New Zealand Standard NZS 6803:1999 “Acoustics -
3 Measured and assessed in accordance with the provisions of Australian Standard AS 2187.2-2006 “Explosives –Storage and use –Use of explosives”. Refer Section 5.3
4 Sensitive times defined in CRL designation conditions 35.1 –35.3 and summarised below 5 Limits may be up to 5 decibels higher for defined periods with the specified notifications detailed in condition 35.2 6 Position representative main presenter(s) microphone and with the doors and windows closed (conditions 35.4/5) 7 These are the measurement locations where required by the Standard. For monitoring, proxy locations can be used with established transfer functions (refer condition 40.9) 8 Measured and assessed in accordance with the provisions of German Standard DIN 4150-3:1999 “Structural vibration –Part 3: Effects of vibration on structures”
9 Limit may be elevated by agreement with MediaWorks as per demolition works detailed in C1.3 dated 25 Nov 2019 Page 9 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs
Page 10 During scheduled live broadcasting During emergency/breaking news live broadcasting During scheduled recording sessions
Live Broadcasting Periods are defined as:
Weekdays: 0600 –0900 hrs, 1200 –1230 hrs, 1730 –1930 hrs and 2230 –2330 hrs.
However, these have been updated by MediaWorks in the consultation overleaf.
Christmas holiday season (Saturday prior to Christmas Day to Sunday following New
Year’s Day inclusive): 1730 –1900 hrs
C1.3 Engagement
Mt Eden Enabling Works (for information)
The building is a terraced commercial building. It features basement car parking beneath 2 –4 levels of office areas overlooking the portal and worksite on the Nikau Street façade. The west façade includes a basement truck dock (lobbied access to Studio 1) beneath office areas at the south end off Ruru Street and editing suites further north, away from the worksite. Studio 1 is in the basement in the middle of the block (i.e. it does not have direct road frontage or access). Other smaller recording studios (including radio and TV) are spread across multiple floors, but also do not front Nikau Street and the worksite. Link Alliance representatives Sonya Leahy, Matt Goldring, Aidan Kirkby-McLeod, Duncan Whyte and Craig Fitzgerald (Marshall Day Acoustics) met with MediaWorks representatives Richard Paul (Property), Darryn Fouhy (Operations) and Emma Michell (Facilities) on 18 September 2019. The matters discussed included:
An overview of the project General programme, demolition, piling, rock breaking/blasting and tunnelling activities
Overview of the CNV DWP and this SSCNMP, communications triggers and protocol
Confirmed knowledge of noise and vibration sensitive spaces, including Studios
Noise and vibration monitor locations agreed and described in Section C1.5
MediaWorks confirmed that the Sensitive Times in the CRL designation conditions do not reflect current operations. MediaWorks provided updated Sensitive Times (received 18 September 2019):
o
o Monday –Friday: Saturday: 0600 –0915,
0900 –1230, 1600 –1700, 1730 –1915,
1700 –1915 2020 –2330
o Sunday: 1700 –1915
Fortnightly meeting (22 November 2019). The discussion focused on the results of attended demolition noise and vibration monitoring in Studio 1 to assess the impact of reradiated noise on broadcast quality. It was agreed that vibration controls applying to Studio 1 could be relaxed to 0.25mm/s PPV during Sensitive Times for demolition activities only (confirmed by email from Darryn Fouhy on 25 November 2019). In addition, the following specific management measures were recommended for demolition phases 1a and 1b only:
Concrete breaking shall not occur during Sensitive Times
Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs
Page 11
Concrete ripping should be limited to 20T excavator The same monitoring process will be repeated for subsequent construction activities before any relaxation is extended (e.g. bored piling, rock breaking, vibro piling). Fortnightly meeting (17 January 2020). The discussion focused on the results of trial vibro roller vibration monitoring. The closest works are predicted to exceed the vibration amenity limit of 1mm/s PPV (discussed further in section C1.4). The proposed period of use of the vibro roller spans approximately 3 weeks. It was agreed that vibro rolling will be timed outside Sensitive Times only. Fortnightly meeting (31 January 2020). The upcoming trial blasting vibration monitoring was discussed. The following were agreed with MediaWorks, Link Alliance and Red Bull:
Blasting times will be at 10.32am and/or 2.32pm.
Red Bull will use GPS time to ensure exact timing to align with radio pre-recorded news broadcast. Blasting envelope is approximately 14 seconds but will still be within the 3- minute window provided.
Red Bull will confirm the radio channel to listen in to the countdown sequence (in addition to the audible site sirens). Fortnightly meeting (31 January 2020). We discussed the upcoming trial blasting vibration monitoring. The following were agreed with MediaWorks, Link Alliance and Red Bull:
Blasting times will be at 10.32am and/or 2.32pm.
Red Bull will use GPS time to ensure exact timing to align with radio pre-recorded news broadcast. Blasting envelope is approximately 14 seconds but will still be within the 3- minute window provided.
Red Bull will confirm the radio channel to listen in to the countdown sequence (in addition to the audible site sirens). Fortnightly meetings (31 January 2020). We discussed the upcoming trial blasting vibration monitoring. The following were agreed with MediaWorks, Link Alliance and Red Bull:
Blasting times will be at 10.32am and/or 2.32pm.
Red Bull will use GPS time to ensure exact timing to align with radio pre-recorded news broadcast. Blasting envelope is approximately 14 seconds but will still be within the 3- minute window provided.
Red Bull will confirm the radio channel to listen in to the countdown sequence (in addition to the audible site sirens). Fortnightly meetings (18 and 28 February 2020). We provided an overview on monitoring results from trial blasting, bored piling and vibro roller operations. We also met with Radio Tarana on 27 February (MediaWorks radio station based in a building at 155 New North Road). We met with Robert Khan to discuss the project and better understand how Radio Tarana operates. Mr Khan advised they have not noticed any impacts from the project to date, and did not have any concerns about upcoming works. Craig explained the potential impacts from noise and vibration and how LA mitigates these impacts with MediaWorks, who are in very close proximity to the project. Mr Khan advised that Radio Tarana is comfortable to be included under the same conditions and mitigations used with MediaWorks. They do not wish to have any special controls. Link Alliance Mt Eden agreed to add Radio Tarana to the C3 distribution list and newsletter list.
Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs
Meeting (19 June 2020). We reviewed blasting monitoring results, vibration alerts and upcoming works. In summary:
Blasting results discussed, including two proximate production blast. One blast event was delayed by an hour due to technical difficulties, and the liaison with MediaWorks to agree alternative blasting time an hour later worked well. No impact on MediaWorks operations. Prerecording of the radio news no longer required because no effect on presenters, guests or broadcast quality.
Review of large number of vibration alerts, mostly false positives. To ensure relevant alert response the following protocol was agreed based on dominant frequency content:
o 0 –2 Hz (earthquake or similar –ignore)
o
o 5 –40 Hz (credible construction vibration –investigate) 48 –50 Hz (local event within building –ignore)
Sheet piling trial in Water St site scheduled for 1 –2 July. Noted that driving to be complete by 4pm to avoid Sensitive Times at Boston Road site. MediaWorks happy to extend demolition alert threshold of 0.25mm/s PPV during Sensitive Times in Studio 1 to all construction activities going forward.
All proximate construction activities ok. Next activity of note that will require in Studio attended monitoring will likely be excavation of the tunnel stubs using a road header or similar. Attended monitoring at MediaWorks to ramp back in near-term.
Mt Eden Main Works
Continue monitoring and engagement, including fortnightly meetings.
This is SSCNVMP necessary because it is within 100m of the works and 200m of blasting activities. CRL Main Works activities are predicted to comply with the noise and vibration limits at MediaWorks site, provided blasting is undertaken at times agreed for the Mt Eden Enabling Works. The following subsections are reproduced from the Mt Eden Enabling Works CNV DWP to ensure consistency.
Noise (excluding Studio 1)
Figures B.1, B.3 and B.5 in Appendix B of the Mt Eden Enabling Works CNV DWP show that the south façade is predicted to be exposed to noise levels between 70 –80 dB L Aeq during the closest demolition, bored piling and concrete breaking activities, exceeding the 75 dB L Aeq noise limit.
The building has a masonry façade with sealed windows, which will mitigate noise received in adjacent office areas. Furthermore, secondary glazing has been installed to further mitigate residual noise levels in office areas on level 2 of the MediaWorks building 10 . The estimated sound level difference across the façade with the windows and doors closed is in excess of 30 decibels. The predicted construction noise effects from Table 12-1 in Section 12.1 are predicted to be typically acceptable, but with the potential for some intermittent
10 Project Agreement in respect of the City Rail Link between Auckland Transport (AT) and MediaWorks Holdings Limited (Mediaworks), reference item 7 and Appendix 2. Page 12 | Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs
Page 13 disturbance for occupants on the southern façade. The performance will be reconfirmed during attended monitoring of early works.
Vibration (excluding Studio 1)
TBM, road header, concrete breaking and rock breaking vibration received in the MediaWorks building office areas, meeting rooms and technical suites is predicted to comply with the 1mm/s PPV amenity limit in CRL designation condition 35.5 (discussed further for Studio 1 below). Vibro rolling is required to form the benching for the portal piling rig. It will be timed outside Sensitive Times only. The relevant area requiring compaction is between 10m and 80m from the MediaWorks Nikau Street façade. Best practice measures to minimise vibration are set out in Section 9.10. Vibration levels of 2.5mm/s PPV are predicted at 10m from the MediaWorks building, exceeding the amenity limit of 1mm/s PPV. A pre-construction building condition survey in accordance with CRL designation condition 46 has been undertaken and will ensure any damage is identified for remediation.
Studio 1 Noise and Vibration
In accordance with CRL designation condition 35.3, if the limits are complied with in Studio 1, the noise and vibration levels in all other Studios will be acceptable. In accordance with CRL designation condition 40.1, high noise and vibration equipment items are identified in Sections 6 and 7 of the CNV DWP respectively. The closest concrete breaking works associated with demolition are approximately 40m from Studio 1 on the south side of Nikau Street. The vibration level from a small excavator mounted concrete breaker (5T) received in Studio 1 is predicted to be 0.1mm/s PPV at 40m, which is at the Studio 1 limit specified in CRL designation condition 35.3. However, it should be acknowledged that these predictions are indicative only and are beyond the reliable tolerances of the prediction method. The closest rock breaking works are approximately 60m from Studio 1 on the south side of Nikau Street. The vibration level from a large excavator mounted concrete breaker (20-40T) received in Studio 1 is predicted to be 0.3mm/s PPV at 60m, which is above the Studio 1 limit specified in CRL designation condition 35.3. However, it should be acknowledged that these predictions are indicative only and are beyond the reliable tolerances of the prediction method. Furthermore, similar C6 rock breaking works were approximately 90m from the Studio with no known effects or vibration exceedances of the 0.1mm/s PPV limit in the Studio.
CRL designation condition 35.2A limits rock breaking used for tunnel excavation within 100 metres during defined Sensitive Times (as defined in CRL designation condition 35.2) unless compliance with the limits in CRL designation condition 35.2 can be demonstrated. While concrete breaking is neither rock breaking nor for tunnel excavation, the first instance of both concrete and rock breaking within 100m will be timed to occur outside Sensitive Times to enable measurement and demonstration of compliance with CRL designation condition 35.2 prior to expanding the works period. This approach aligns with the requirements of CRL designation conditions 40.3 and 40.8 and addresses any residual risk of exceedance. TBM and road header activities also have the potential to marginally exceed the Studio 1 limit specified in CRL designation condition 35.3 depending on the finalised alignment. These tunnelling activities have the potential to generate vibration induced reradiated noise (a low frequency rumble). The vibration transfer function will need to be established once the
Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs
project starts as it cannot be readily predicted with any accuracy. This will be monitored to ensure compliance. It is noted that the 0.1mm/s PPV vibration limit primarily controls reradiated noise levels to below 30 dB L Aeq (5 min) and 33 dB L Aeq (1 sec) specified in CRL designation condition 35.2. This relationship was established in an SLR report during the CRL hearings process 11 . It determined that the airborne noise component received in the Studio was negligible (transfer function in the order 80 decibels) and that the only residual noise effect would be from reradiated noise. This relationship will be used as the initial basis to satisfy designation conditions 40.2 and 40.3, however, will be reviewed following monitoring of the first occurrence of concrete breaking (described in the previous paragraph). Blasting and vibro rolling will be timed to avoid sensitive times.
C1.5 Studio 1 Monitoring
Overview
Noise and vibration monitoring inside Studio 1 shall be undertaken by a suitably qualified and experienced acoustic specialist in accordance conditions 35 and 40. This shall include continuous automated monitoring in accordance with CRL designation condition 40.9. The data shall be available in real time to City Rail Link Limited, Link Alliance, Auckland Council and MediaWorks.
Any additional proxy noise and vibration controls shall be determined, and agreed upon by MediaWorks, that enable on-site compliance management. The proxy controls shall be determined in accordance with designation conditions 40.2 and 40.3 and included for reference in the Tables C1.2.
System Setup
The automated monitoring systems measure continuously. The data is uploaded to a secure website (or similar) for access by key personnel. The systems also generate automated email/text alerts for any exceedances. In addition to the automated monitoring, attended monitoring will be undertaken during the first occurrence of concrete breaking activities within 100m of MediaWorks. This will enable verification of the measured levels in Studio 1 and inform subjective impressions of resulting effects. It will also inform the transfer functions for this activity between the demolition sites and Studio 1. The transfer functions may allow subsequent measurements during the remainder of construction period to be undertaken at other locations. These would be the ‘proxy’ locations and would be reviewed and agreed upon by MediaWorks prior to their use. Monitoring may occur at locations simultaneously or sequentially provided the vibration sources of interest are captured, and compliance with the conditions can be demonstrated. The monitoring locations may change over time to accommodate different phases of construction, but throughout there will be a consistent focus on Studio 1. Vibration measurements are likely to be influenced by other activities causing vibration in the building (e.g. people walking past the transducers, moving equipment, doors slamming etc.). These ‘false positives’ can be managed in the first instance through appropriate placement of the monitors but can also be managed by processing the data statistically or comparing simultaneous monitoring data from the two vibration monitors in the building to ensure these anomalous events are not interpreted as construction events. The trigger
11 SLR report Mediaworks Investigations Borehole and Studio Vibration, Page 14 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs 610.12219.00400-R1, dated 21 October 2013
threshold for text/email alerts may also be modified as appropriate to reduce the number of ‘false positives’ in accordance with CRL designation condition 35.3 by agreement of both the Requiring Authority and MediaWorks.
Monitoring Locations
The monitoring locations agreed in consultation with MediaWorks are as follows:
Studio 1 Vibration monitor
L1 Store Vibration monitor
Roof Noise monitor
Monitoring Equipment
Construction vibration will be monitored using Syscom MR3000C units. The units would typically be placed on the basement floor near the façade closest to the construction works and/or in Studio 1. Alternatively, they may be placed on the top floor near the same façade. They do not require fixings (i.e. clamps, adhesives) to be installed, however weighing down with a sandbag is recommended. They are best located away from foot traffic to avoid being bumped. The units record numerical vibration levels. The data is accessed remotely via the 3G network. If a preset monitoring trigger level is exceeded, it will alert the monitoring manager.
Construction noise will be measured using a Svantek SV307 Noise Monitoring Terminal (NMT). An external microphone will be placed on the outside of the façade that faces the construction works. The unit records numerical noise levels. The data is accessed remotely via the 3G mobile phone network. If a preset monitoring trigger level is exceeded, it will capture a short audio recording and alert the monitoring manager.
Page 15 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs
Review of the monitoring data and audio may help identify the source and inform construction methodology, mitigation opportunities and communication.
With mains power, the units operate autonomously, only requiring access for yearly maintenance and calibration. The units use a conventional house plug and draw between 2 and 3.6 watts of power, which is similar to a mobile phone charger.
Alert Response
A separate document will detail the people who are setup to receive the text and/or email alerts, provides access to the vibration web monitoring system, and the alert response protocol. It will be provided separately from this SSCNVMP because it contains sensitive information.
C1.6 Contingency Measures
As required by CRL designation condition 40.11, where any of the noise and vibration limits for Studio 1 in conditions 35.2, 35.3, 35.7 and 35.8 are exceeded, and where the noise and/or vibration levels are unacceptable to MediaWorks, the following corrective action measures shall apply:
Cease the work giving rise to the exceedance as soon as safe and practicable to do so
Review the construction methodology, mitigation and management strategies to ensure they represent the BPO and reduce the noise or vibration levels
Monitor to determine compliance once the remediation works are complete
Ensure that the work responsible for the exceedance is not recommenced during Sensitive Times
C1.7 Review Process
This SSCNVMP will be updated in accordance with CRL designation condition 40.13, with consideration given to the following:
The extent to which noise and/or vibration may exceed the designation noise standards
The timing and duration of any exceedance
The type of activity causing any exceedance
A summary of the communication and consultation with the MediaWorks The methods and measures to mitigate noise and/or vibration effects
A statement of why they reflect best practicable option Communications records are contained in the communication and consultation plan (CCP). This SSCNVMP will be updated to summarise engagement and any agreed site-specific measures.
Page 16 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs
