Reviewing the curtailment of 24-hour tunnel boring due to groundborne noise and vibration effects in overlying residences
The Dublin Port Tunnel is a 4.5-kilometre-long twin bore road traffic tunnel in Dublin, Ireland, that is part of the M50 motorway. Sections of the tunnel run beneath residential areas of the city.
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The Challenge
During construction of the tunnel, significant groundborne noise and vibration issues arose as a result of boring through hard rock lying beneath residential communities, resulting in the withdrawal of permission for 24-hour working during tunnel construction. The contractor pursued the employers for 16 million Euros in compensation damages following completion of the project.
RWDI’s noise, acoustics, and vibration team was brought in to act as expert witnesses on behalf of the Dublin Port Tunnel project’s employers, the Irish National Roads Authority and Dublin City Council.
Our Approach
To determine whether the project manager acting on behalf of the employer had been correct in stopping construction from proceeding around the clock, our team:
- Performed an in-depth investigation into anticipated and measured groundborne noise and vibration that occurred during the tunnelling work.
- Interpreted the levels and the likely subjective response from residents.
- Represented the client at a series of informal and formal hearings between the project manager and the contractor.
- Presented expert testimony at Conciliation and District Adjudication Board (DAB) hearings.
The Outcome
By using the contractor’s own monitoring results, RWDI’s noise, acoustics, and vibration team successfully demonstrated that the project manager had acted reasonably in curtailing tunnel boring working hours. The DAB agreed with the employer’s evidence presented by the RWDI team and the contractor withdrew its claim.