Luas Cross City extension, Geospatial management | Murphy Geospatial

Project Title:

Location:

Dublin City

Client:

Sisk Steconfer JV

Business Sectors:

Civil Infrastructure

Services (Technical Disciplines):

Survey
Engineering
Geospatial Data Collection

Project Objectives/ Outcomes:

This critical piece of urban infrastructure links up two existing light rail corridors in Dublin city centre comprising of 5.9km of new track, 13 new stops and associated works. Murphy Geospatial were the Geospatial Managers for the entire project working in partnership with the Sisk Steconfer JV. Geospatial certainty throughout the life cycle of the project, managed reliably by an experienced Murphy Geospatial team, was a key reason this project was delivered on time and on budget.

Our Role:

Murphy Geospatial played a critical role in the success of the project, delivering surveying and engineering services during the design and construction phase. Our Head of Digital Construction, Michael Durnin, acted as Chief Surveyor with SS JV and oversaw every aspect of survey and geospatial data collection including establishing the control network, all setting out works, deformation monitoring and subsurface mapping.

Early engagement and collaboration during the pre-construction phase was the key to success. Murphy Geospatial strong and trusted relationship with the Sisk Group over years of working together was also instrumental.

Technical sensor driven solutions were used to automate the data capture process. Compared to more traditional methods this reduced risk, cost and optimised efficiency. Data management workflows were also integrated into the project which increased on-site efficiency and productivity.

Challenges during the project included TII’s construction specifications. 1mm relative change over 1m of track was an extremely tight tolerance for rail construction. 1:60,000 linear accuracy and 5√k for control are both very difficult to achieve in a heavily urbanised environment and in phased construction works.

The specification also included localised variables for paving under tight constraints where real-time decisions against design were made by the setting out teams.

Despite facing tight constraints and the challenges of such a large and complex site, the survey works were completed to a high standard in line with the specification.

Key Construction Statistics

Total single line track: 13.4km
Total weight of the tracks: 1,520 tonnes
On street, concrete track bed and shoulders poured: 13,600m3
Total ducting and pipes under the surface: 178,000m
Projected total man hours to complete SSJV works: 3 million hours

Geoscience Ireland Contact:

Dave Graham (dgraham@murphygs.ie)