10Trinity Square is a design build project which involves the refurbishment, conservation and extension of a Grade II listed building in the City of London into a 140 bed 5-star hotel, with 41 serviced luxury apartments. Construction consists of structural refurbishment, traditional new-build and modular new-build.
Works commenced in 2012 and are currently ongoing. The project is within a confined city centre site. There are 4 additional floors being added on. These are to be supported on a steel transfer structure at the existing fourth floor. The critical criterion for the steel design at transfer level is deflection as this affects the entire structure over. A normal steel transfer solution would have resulted in exceptionally heavy steel beams at that level.
Services provided by BMCE:
BMCE devised a bespoke method of pre-loading the steel beams to pre-deflect the beams by the equivalent deflection that would have been caused by the dead loads of the super structure over thus reducing the on-going deflections to those induced by live loads only. This had the effect of reducing the steel tonnage by approximately 35% – in monetary terms about 65 tonne at, say, a value of £2,200 per tonne = £143,000.