Downwell have just completed a 12 possession demolition of the Stratton St Bridge in Biggleswade, Bedfordshire. The project comprised of the removal of all of the road surfaces, the parapets, breaking free the concrete panels before finally lifting out the concrete panels that made up the deck.
Scope of Works
- Small enabling works had to be completed to allow for the services to be diverted out of the bridge deck. The walls either side of the bridge deck had to be demolished to allow for the temporary services deck to be installed.
- The bridge was closed and the traffic was diverted around an alternative route.
- The paving slabs and iron bollards that were running the full length of the bridge on either side were carefully removed and salvaged for reinstatement later.
- The asphalt surface was removed using a road planer. The material was removed from site and recycled at a local recycling facility.
- The joins in the concrete panels that made up the deck were saw cut 75% of the way through. The fixing down bolts were also exposed by breaking the concrete away from around then.
- During the the first full night time possession a scaffold deck was erected beneath the bridge, spanning the entire underside of the bridge. The brick parapets were demolished using a 5 tonne excavator. The arisings were loaded into boat skips before being lifted off the bridge deck.
- The final 25% of saw cutting was completed on the panels to be lifted out following the pre defined lifting sequence. The holding down bolts on the panels to be lifted out were cut using oxy-propane cutting equipment.
- Over the next several possessions the concrete panels were lifted out using the 220 tonne & 180 tonne mobile cranes which were positioned on both ends of the bridge.
- Both cranes were operating simultaneously to lift the concrete panels out in the pre defined sequence. The panels were lifted onto waiting flatbed lorries. They were then transported to a n off site facility for processing and recycling.
Stratton St Bridge
Biggleswade, Bedfordshire, SG18
12/15 - 03/16