Necessary works carried out to maintain this vital link into Poole
On the Towngate Bridge project, the bearings supporting the bridge onto the abutments were badly corroded and needed replacing. The bridge is a crucial link through the town centre of Poole and therefore, the replacement works required had to keep any disruption to a minimum.
Initially, a design and AIP were produced for the contract with the major design aspect needed to provide lateral restraint to the abutment. This was achieved by the installation of a steel frame which was bolted to the abutment wall and clamped round the existing bridge structure. Following removal of brickwork that masked the bearing surroundings, hydraulic jacks were positioned, as per the agreed design, on either side of each of the bearings. Traffic Management closed the bridge at night to allow the hydraulic jacks to be mobilised and lift the bridge off its bearings before locking off the jacks. At all other times, traffic flow was maintained.
Protection was erected around the bearing areas to ensure both the safety of the public and the structure. Hydro-demolition was then used to break out beneath existing bearings to release them.
The new pot bearings were then carefully fixed into a level position and fixed to the bottom flange of the beams using a flowable grout. An epoxy bed was also fixed beneath the bearings on top of the flowable concrete that had been used to reinstate beneath the bearings on the bearing shelf. The traffic management was carried out by the council for the actual jacking and de-jacking operations. An STU hydraulic unit was also replaced in line with all the bearings.
Some concrete repairs were also carried out to the abutment structure as part of the contract.