LOCATION:
A 400m long, 4m wide floating shared walkway and cycleway along Bristol Harbour. The walkway is connected to the land at each end via concrete landing platforms and a series of ramps and gangways that accommodate fluctuating water levels. It was awarded under an NEC3 Option A design and construct contract by Bristol City Council.
A design and construct contract for a 400m long, 4m wide floating shared walkway and cycleway along Bristol Harbour.
- Poured PC concrete foundation blocks.
- Injection dredging.
- Harbour bed improvement with shingle to prevent settlement.
- Installed anchor block foundations, lifted onto the harbour bed storage area, collected by barge, and floated into position.
- Installed scour protection, ground anchors, and mooring posts by divers.
- Installed tubular piling for the ramps and gangway support lintels and bearings from temporary stone causeways.
- Cast both north and south concrete landing platforms.
- Floated in the pontoons, delivered by sea into Avonmouth Dock and brought up Bristol Harbour one at a time.
- Installed the ramps and gangways using a crane on a floating barge.
- Associated M+E.
- Bank stabilisation works.
Challenges
Soft harbour bed conditions: Foundation blocks sinking and slipping into the channel.
General methodology: Site constraints; limited access to the water, width of the channel, and low-level bridges.
Access for the piling rig.
Bank collapse.
Solutions
- Redesign for river bed improvements: Stone was placed on the harbour bed by an excavator on a floating barge supplied by a hopper barge. Additional steel ploughs and other materials were installed to the underside of the foundation pads to prevent sliding.
- Specialist plant and equipment sourced to overcome constraints, often delivered in modular sections and bolted together on the water.
- Numerous meetings with the Environment Agency to agree on the Flood Risk Activity Permit for constructing a stone causeway to provide access for piling equipment.
- Full design for the chosen solution and applications for planning and Marine Management Organisation licences, with construction undertaken by divers and floating plant.
Outcome
The completion of the work will provide a scenic walkway granting access from the new university buildings to Bristol Temple Quarter.
