OCSC

Dail Éireann

This project was commissioned to provide 10,000m2 of offices and committee rooms for Oireachtas Members and is located on the former National College of Art and Design site between the National Library, Leinster House and the National Gallery of Ireland.

Contract A included the demolition of the old National College of Art and Design buildings, service diversions, relocation of car parking on Leinster Lawn plus piling and temporary works.  An opening was formed in the 7m high historic curved stone wall between the site and Leinster Lawn to give a main site access route onto Merrion Square.  A temporary façade retention system was erected to provide additional support to the curved wall during the contract period.  The most significant part of Contract A works was the installation of a secant piled wall (600mm diameter) tight to the historic buildings and curved wall surrounding the site. Over 215 linear metres of piling was completed in 7 weeks.

 Contract B, the main building works, included the excavation (and associated temporary works) of over 12, 000 cubic metres of soil.  The 7.0m deep Grade 4 basement, housing the committee rooms consisted of a reinforced concrete box structure founded in black boulder clay.  Rock anchors were socketed through the basement slab through varying depths of black boulder clay into the limestone bedrock to act against long term buoyancy.  The new build works consist of 6 and 7 storey RC structures in the form of 2 main linked blocks laid out around a central garden and pool feature at ground floor level.  The floors were generally designed as 300mm deep flat slabs without drops on a 7.2m x 7.2m grid with stability provided by lift and stair cores located at the four corners of the structure.