Paddington Central Buildings



Location: Paddington, London

Client: Development Securities PLC / Skanska

Scope: Design & Install Post-Tensioning

Paddington Central is located on the former Paddington Goods Yard along the northern side of Kingdom St and south of the A40 Westway, Paddington. With its striking architecture by Kohn Pedersen Fox Architects and structural design input from Arup, it has been developed to the highest levels of sustainability and is expected to receive the highest BREEAM rating of 'Excellent'.

Comprising of three basement levels and ten storeys, of which all were post tensioned, the structure makes an impressive addition to the Paddington Basin Development in West London.

Developed by Development Securities PLC and built by Skanska, the building is part of a major regeneration project around the new grassy amphitheatre of Sheldon Square.

Structural Systems were brought in by the frame contractor, P C Harrington, to advise on a suitable system for the post tensioned floors. SSL proposed their 505 Slab bonded post tensioning system utilising 15.7mm strand, with 3 to 4 strands per anchor. Work on the scheme started in 2008 with completion in 2009.

There were numerous design and construction issues to overcome. The basement levels and podium had numerous steps which ranged from 500-800mm in depth. This made the installation of the post tensioning more difficult and required a great deal of co-ordination between all parties involved in the design and installation. The design also demanded 3 to 4 different slab depths on the podium level ranging from 275mm to 325mm, to cater for varying spans and loading conditions.

The building is a complex shape, with internal penetrations of 18.65m x 2.1m. To further complicate issues, there is also a 3.2m long cantilever to cater for. Typically, the structural layout required spans of 9.65m x 9m but in some cases, this increases locally to 11m.

At the rear of the building on Level 0 a 9.65m long x 450mm deep x 1200mm wide PT beam was required to transfer a significant point load.

Internal pans were used on Level 0 due to the limited access to the edge of the slab and again, a range of slab depths from 275-400mm was required.