Construction of our new civic precinct Te Manawataki o Te Papa is progressing. This week construction on the civic whare (public meeting house), museum, and exhibition gallery started, joining Masonic Park and and the new library and community hub which are already under construction.
Sheet piling works started along the Hamilton Street side of the site earlier this week. Installing sheet piles causes vibrations in the ground, and you may notice increased noise levels at times.
Sheet Piling
We expect that installing sheet piles will cause the most disruption over the next few weeks. Sheet piling is a system that uses steel sheets ground to retain the earth. The steel sheets are pushed into the ground using a vibrating head on an excavator this process is noisy. Sheet piles will be installed along Hamilton St to support the road while the building is constructed. There are also some other sheet piles in the middle of the site. While our contractors will be using the quieter method of installing sheet piles, it is still noisy – particularly when the sheets are first being lowered.
Installing sheet piles has lots of uncertainties as the pilers will be dealing with variable ground conditions and possible unknown obstructions. Our expectations and plans are:
The Sheet piling started Monday 17 June and is expected to take approximately 5 weeks.
- The works have started opposite the Watts & Hughes carpark site and will head down Hamilton St. All going well, this first stage will be completed by 28 June. This stage is closest to Harrington House and Willow St.
- The second stage of sheet piling is perpendicular to Hamilton St and starts opposite the carpark site.
- The third stage of the works are planned to start opposite the Watts & Hughes carpark site, head up Hamilton St and then turn into the construction site. We expect this final stage will be completed by 20 July. This stage is closest to Quest, Kingsview Towers and Baycourt.
Once the sheet piling is complete there will be a break of several weeks (hopefully at least 6 weeks) before the ground improvement works commence in September. We will provide another update prior to this work starting.
Vibration
People can feel even very small vibrations and may feel disturbed by the vibrations. In general, the further away the piling works are the less vibration is felt.
Installing sheet piles causes vibrations in the ground which will be noticed by neighbours. These vibrations levels are significantly lower than anything that would cause structural damage. Vibration measurements are being taken by specialist Marshall Day Acoustics, to check that their predictions are accurate.
Tips for reducing vibration disturbance:
- If there are articles nearby that rattle due to the vibration, take steps to stop the rattle. When you hear a vibration, it tends to feel worse.
- Certain locations of the building may transmit the vibrations more. For example, during a previous project in one building we found vibration levels measured near the core were far lower than those experienced mid floor span.
- Sitting on a soft seat may transmit less vibration than a seat with no padding. Likewise, a seat on carpet with underlay may transmit less vibration than a seat on a timber floor or bare concrete.
Noise
Our consent requires that when noise can’t be kept below the thresholds prescribed in NZS 6803 1999, measures must be taken to reduce the effects. For the purposes of this project, we have assessed the thresholds as 70 dB LAeq and 85 dB LAFmax as we are thinking about the total project duration and not just the noisy stages.
Here is what we are doing to both stay under the thresholds and reduce the effects if they are exceeded:
- The least noisy machinery and construction methodologies have been chosen
- Noise blankets have been installed along Hamilton St
- Noise measurements are being taken by specialist Marshall Day Acoustics, to check whether their predictions are reliable
- There will be a break of several weeks between the sheet piling and the start of ground improvement works
- Regular updates will be provided via this blog so our neighbours can follow the rate of progress
- All workers on the site receive an induction which includes information about noise management
- Noise management is an agenda item for the regular site Toolbox talks
- Signage will be erected on site to remind workers of the time restrictions
Thank you
We are aware that the construction activities will have an impact on our neighbours, and we are very appreciative of your tolerance.
Te Manawataki o Te Papa - Construction Updates 