A CHALLENGING £11M bridge deck strengthening project in Glasgow was nearing a major milestone this week as contractors prepared to lift a curved access ramp off its supporting columns.
Main contractor Graham Construction is fixing jacking frames around four concrete columns supporting the curved central section of the Stobcross on-ramp.
The ramp leads to Kingston Bridge, which has been undergoing strengthening and repair work since 1992. Six years ago the main deck was successfully strengthened by post tensioning (NCE 28 October 1999). This latest stage is funded entirely funded by the Scottish Executive.
The jacking frames will help with the operation to lift the entire post tensioned curved central section of on-ramp off its bearings within the next few weeks.
This will allow contractors to begin a complex operation to strengthen it with external stressing tendons later this year.
'We are demolishing and replacing the straight sections of deck at each end of the 150m long curved section, but these aren't above the M8, ' explained Glasgow City Council project manager Ian MacGregor.
'Demolition of the central section would have involved unacceptable traffic disruption on the motorway. So we're adding extra prestress via external tendons - as far as we know this has never been done to such a tightly curved deck before.'