Sanderson Watts Associated (SWA) was appointed to produce an options report for the improvement of the deck structure of Langwathby Bridge, a 3 span masonry arch bridge used primarily by farmers and their vehicles.
The improvements were required to accommodate a deck drainage scheme to achieve a waterproof structure as it was found that the system in place was inadequate resulting in the implementation of remediation techniques to combat freeze-thaw effects which had taken place.
The deck space is split into two lanes of approximately equal width by a handrail denoting a separation in traditional access across the structure by adjacent landowners. The deck infill material is comprised largely of mud and stone. The level of the infill between the south parapet and the handrail is approximately 300-400mm higher than the north parapet and the handrail.
Key Challenges / Solutions:
• Identify, as accurately as possible by visual survey and MEXE analysis the general structural condition and integrity of the bridge giving consideration to future structural substantiation and any vehicle restrictions.
• Strengthening the deck structure & installing a deck drainage system whilst keeping all owners of the bridge happy with the reinstatement of the handrail once the work had been completed. This also had implications on the maximum vehicle restriction along the bridge.