This project was a tender design for DBMFO contract for an 18 km long metro line from Dublin Airport to the heart of Dublin city center. About half the distance was planned to be underground in two separate bored tunnels. Next to the twin bored (app. 7 m OD) tunnels 7 deep subsurface stations were planned to be executed. The geology of Dublin consists of glacial till deposits overlying Carboniferous bedrock consisting mainly of limestone and shales. The Carboniferous rocks are heavily folded, faulted and jointed. The bedrock level is also strongly undulating. The tunnels and stations were to be constructed largely within the Carboniferous bedrock.
Scope of work
The construction of geological long sections along the entire alignment on the basis of about 400 soil and rock borings
- Compilation of a geotechnical interpretative report
- Preliminary design of TBM alignment and tunnel cross section
- Geotechnical/structural design of 5 deep subsurface stations
- Settlement risk assessment studies
- Advise on TBM type and mitigating measures