UNDERGROUND SPACE

Taking Development Underground - Solving Urban Problems With Innovation

Population growth, urban development and the requirement for environmental preservation have led to underground space becoming increasingly important in solving urban problems. ByrneLooby has been involved in a wide range of projects in the underground space sector, providing design services to clients throughout the project cycle from initial concept design through to detailed design and construction supervision to solve critical infrastructure needs. Our team of geotechnical engineers, structural engineers, engineering geologists and civil engineers deliver project and client requirements in areas such as tunnelling, deep shafts, temporary works, retaining walls in a variety of ground conditions throughout Ireland, the UK and the middle east.

Our team of engineers are regularly involved in challenging and complex projects working directly for developers, as well as supporting contractors with design and build services. In Qatar, our role included the selection of the tunnel alignment and shaft locations and the design of permanent and temporary shafts for the Lusail Expressway. While, as part of the Elan Valley Aqueduct, we designed several TBM (tunnel boring machine) launch and work shafts including a 30m deep, 13.5m diameter permanent secant pile wall-drop shaft.

As part of the New Children’s Hospital project, in Dublin, our appointment included the detailed design of close to 1km of permanent secant pile wall for the triple-level basement. Through close collaboration with our clients and technical expertise and experience in this area, we provide efficient and effective design solutions.

Crossrail Eastern Running Tunnels

Deepham’s Shaft, London, UK

PROJECT FOCUS: CONSTRUCTION OF STEPNEY GREEN SHAFT USING DEEP DIAPHRAM WALLING TECHNIQUES

STEPNEY GREEN CROSSRAIL

OVERVIEW

The new Crossrail line in London divides at Stepney Green, with one line continuing north and one line crossing the Thames to the south. A deep shaft and large mined cavern was required at this location as TBM reception and launch and to accommodate the converging tunnels. The shaft was constructed using deep diaphragm walling techniques. The tunnel crosspassages are some of the largest ever constructed using sprayed concrete lining, being 50m long, 17m wide and 15m high.

PRIMARY ROLE

ByrneLooby was initially appointed by the specialist contractor SPIE UK to design and detail the diaphragm wall. This wall facilitated the enormous 35m deep excavation, with the wall panels being 1.2m thick and 50m deep. A particular challenge was the detailing of the reinforcement for the wall panels, ensuring these large cages could be safely lifted from horizontal to vertical for placement into the excavation. Each cage weighed 25 tonnes necessitating a robust temporary works design.

EXPERTISE

Subsequently, the main contractor Dragados-Sisk JV appointed ByrneLooby to design the temporary propping to facilitate excavation of the shaft. We worked collaboratively with Dragados-Sisk to devise the value engineered construction methodology and sequencing and internal support system in order to accelerate the construction program and improve buildability. ByrneLooby also provided guidance on the cross-passage excavation stability and the sprayed concrete lining solution. Location: London, UK Capital Value: Undisclosed Project Name: Stepney Green, Crossrail Country: UK Client: SPIE UK

PROJECT FOCUS: 23M DEEP PUMPING STATION ON DIYAR AL MUHARRAQ

DIYAR AL MUHARRAQ - PUMP STATION

OVERVIEW

As part of the sewer network upgrade in the Kingdom of Bahrain, a 23m deep pumping station was constructed on the man-made reclaimed island of Diyar Al Muharraq. To enable the construction of this pump station a 23m diameter shaft was constructed using 900mm interlocking male and female secant piles.

PRIMARY ROLE

ByrneLooby undertook a detailed design review and value engineering exercise for the deep shaft. This included an independent check on the process design and the structural design, a geotechnical assessment of the proposed solution along with the overall final configuration and suitability. Advice on the dewatering strategy in this aggressive marine environment was also provided, including consideration of pile overlap, drilling methodology and the degree of water cut-off that could be achieved. Location: Diyar Al Muharraq Capital Value: Undisclosed Project Name: Diyar Al Muharraq - Pump Station Country: Bahrain Client: Undisclosed