URBAN GEOTECHNICS

Maximising constricted urban spaces with innovative underground solutions

For over 20 years, ByrneLooby has successfully worked on urban projects across various ground conditions by supplying geotechnical engineering and below-ground design services. Our team consists of geotechnical engineers, civil engineers and engineering geologists who deliver tailored solutions to meet individual urban project and client requirements. We have extensive experience in design and construction in various ground conditions throughout cities in Ireland, the UK and the Middle East.

Advising Innovative Solutions

Cities worldwide are struggling with a myriad of environmental and social problems with air, water and soil pollution and crowded, ageing infrastructure. Innovative solutions are essential to combat these problems by utilising underground solutions and maximising space.

Our geotechnical engineers contribute to exciting and challenging projects, many of which are major national and international schemes built within densely populated areas. In the buildings sector, we have provided foundation and basement designs for The Shard in London, the New Children’s Hospital in Dublin and the visitor centre at Titanic Belfast.

Often, we apply complex 3D modelling on projects to understand the impact on surrounding assets due to potential ground and structural movements. We provide detailed earthworks and sub-structure solutions for large urban infrastructure schemes such as the Crossrail line extension in London, the Doha Metro scheme in Qatar and the M50 widening in Dublin.

Our expertise covers all aspects of geotechnical and geological engineering, from planning, investigation and feasibility studies to design, construction surveillance and operations and maintenance.

University College London Hospitals (UCLH), UK

60 Dawson Street, Dublin, Ireland

PROJECT FOCUS: AN ARCHITECTURAL ICON AND WESTERN EUROPE’S TALLEST BUILDING

THE SHARD

OVERVIEW

One of London’s most iconic landmarks, The Shard is a striking silhouette in the skyline. As one of the tallest buildings in Europe, The Shard reflects the ambition and vision of the City. With its location in the heart of London, any works on The Shard risked a considerable impact on its neighbours; most notably the adjacent London Bridge station, a Victorian structure and integral transport hub for the city.

PRIMARY ROLE

ByrneLooby was appointed as the detailed designer for the substructure, including a top down construction sequence for the triple level basement. As the project is adjacent to London Bridge station, a central hub on London’s rail network, the rail authority (Network Rail) required detailed analysis of the effect of the basement excavation on the Victorian station structure. ByrneLooby undertook a detailed Ground Movement Assessment and successfully satisfied Network Rail and their technical advisors, gaining approval for our design.

INNOVATION / VALUE ADD

The solution designed by ByrneLooby included a secant piled wall to allow for the deep excavation, piled foundations, and plunge columns. The original foundation concept involved the piles being base grouted. Following a successful preliminary pile test to record settlements and strains, ByrneLooby argued that base grouting was not necessary and provided a value-based alternative. The final solution comprised 60m deep, 1.8m diameter, bored piles founded in the underlying Thanet Sand. Location: London, UK Capital Value: £350m Project Name: The Shard Country: UK Client: Balfour Beatty Ground Engineering

PROJECT FOCUS: ENGINEERING A 23,000M3 EXCAVATION IN THE CENTRE OF DUBLIN

60 DAWSON STREET

OVERVIEW

Project Kells is a large retail and office development in Dublin City Centre at Dawson and Nassau Street. The proposed works includes the construction of a new, four to six-story high mixed-use building. As part of the redevelopment, it is proposed to complete a bulk excavation for a two level below ground deep basement.

Two sides of the proposed basement are parallel to the LUAS Cross City Line, at the junction between Nassau Street and Dawson Street. The basement is approximately 3.4m to 7.1m from the nearest LUAS running rail. In the temporary case, excavations of 10.15m to 10.75m bgl are required.

PRIMARY ROLE

ByrneLooby worked closely with the clients (PJ Edwards) from the tender stage providing consultancy services covering design methodology, monitoring, and detailed design of the secant pile wall and temporary support to the wall during construction.

To facilitate installation of drainage and services, excavation depths up to 10m and 11m bgl have been accounted for in the temporary case. The designs had to meet tight movement criteria and we proposed a real time instrumentation system, to ensure that the works had no adverse impact on adjacent sensitive structures and the live LUAS light rail line.

ByrneLooby also completed the design of permanent works foundation piles. The installation of foundation piles was required to accommodate large compression loads where the top of bedrock was well below the basement formation level.

ByrneLooby also completed the design of the capping beam for the temporary works to distribute the support from the temporary propping and tie back anchors along the secant pile wall. Extensive studies were also done on the possible construction methods for constructing the pile caps and piers in the marine environment. Both bridges were designed using post-tensioned concrete box girders of uniform depth – each carrying 2 lanes of traffic, with inclined piers supporting the spans over water and vertical piers for spans over mud flats. Location: Dubin, Ireland Capital Value: €58m Project Name: 60 Dawson Street Country: Ireland Client: PJ Edwards & Co. Ltd.