Refurbishment of railway bridge in East London

thumb_topbond_first_projects_bignold_road_croppedBignold Road Bridge is a 23.5m single span underbridge carrying non electrified railway lines over Bignold Road in East London. As part of the East Anglian framework agreement, Topbond were asked to replace the existing load bearing abutment arrangement with a new concrete-encased steel beam arrangement.

Topbond carried-out the following works:

Excavation and casting of temporary bridge deck-prop R/C foundations at four locations, done sequentially to prevent the risk of abutment movement.

Removal of 1 No. brick pilaster and subsequent rebuilding with original bricks and caps.

Temporary propping of the bridge adjacent to the abutment (outside rail possessions).

Jacking the bridge sequentially as work progressed to remove concrete bedstone and brickwork to the designed levels then place and fix steel grillage and bearings. No jacking loads were applied except during rail possessions (5 No.). Steel beams were blocked and tied to prevent movement. The alignment and level of the bridge was monitored and recorded throughout.

Removing the existing stone and concrete bed stones and brickwork sequentially to the required level.

Installing prefabricated steel trellis in sections at bridge bearing locations.

Fixing steel reinforcement to steel trellis, formwork fixing and concrete pumping in to form a new R/C cill beam.

Finally, steelwork repainting and abutment wall brickwork repairs were carried out as required.