Metrolink Utility Investigations, Dublin, Ireland

Client
> Transport Infrastructure Ireland

Sector/Market
> Infrastructure, Utilities

Services
> Subsurface Investigations, Underground Utility Surveys

Location
> Dublin, Ireland

Project summary

Transport Infrastructure Ireland plan to construct a new Metro rail line from Donabate to Charlemont in Dublin. Murphy Geospatial was engaged as the main survey consultant at the planning and design stage of this major Infrastructure project across Dublin City. The survey zones extended from Ballymun in the North to Charlemont in the South.

The brief

The project brief included PAS128 underground utility surveys at the proposed locations of Metro Stations along the route. Murphy Geospatial was tasked with locating buried utilities and producing an attributed GeoBIM model illustrating the results.

The control network was installed under a separate contract and Murphy Geospatial utilised this network to coordinate all survey data throughout the project.

The challenges

Several very large manhole chambers were present within one of the survey zones which offered very limited visibility, so Murphy Geospatial scanned these chambers by means of using a Laser Scanner on an inverted tripod and provided the best information possible in a difficult working environment. This avoided the need for high-risk confined spaces entry for all staff involved.

Our work

Murphy Geospatial was granted access permission from all the utility providers in advance of commencing the surveys. The utility providers also provided copies of their record drawings at the outset of the project. Once all utility record drawings were available, Murphy Geospatial mobilised to site and undertook a Site Reconnaissance survey in line with the PAS128 Underground Utility Detection specification. Following this, a report was drawn up and delivered to the client. This report was reviewed and discussed prior to mobilising survey crews to commence the detection surveys.

The survey zones included urban, extra-urban, greenfield sites and rail lines. Traffic Management was implemented for all works requiring access to roads, under permission from Dublin City Council. Iarnrod Eireann (Irish Rail) provided supervision for works on rail lines.

Murphy Geospatial commenced data processing one week after mobilisation of the survey crews. During processing the data was checked using in-house developed scripts which check certain aspects of the data to ensure the quality of the survey. Various processing software packages were employed including Trimble Business Centre, AutoCAD and Civil 3D.

The finalised dataset was delivered in the form of an attributed AutoCAD Civil 3D model, with additional formats provided for use in Bentley Microstation and ArcGIS. All deliverables were specifically developed for this project, and Murphy Geospatial also developed software to convert the Civil 3D models to Bentley Microstation and ArcGIS formats while maintaining all of the attribute data associated with infrastructure elements within the models.

Results

Each survey deliverable was reviewed by the relevant Department’s Quality Control Manager, in line with Murphy Geospatial procedures. All Quality Control Checklists were completed, approved, and filed in the relevant project file folder.

The client employed Jacobs Engineering to review all survey deliverables before providing feedback to Murphy Geospatial. Several meetings were held throughout the final weeks of the project where the surveys were discussed and explained. We provided Geospatial Certainty, enabling the client to swiftly move to the design stage of the project.

Contact

For more information on this project, please email info@murphygs.ie or call us on +353 (0)45 484 040