Conisbrough Railway Bridge Maintenance
A steel support platform designed by VEDA was attached to an unused Network Rail (NR) bridge pier located in the river bed in Doncaster to investigate its integrity and the foundations of the structure.
Built around the middle of the 19th Century, the three-span bridge is located on the outskirts of Conisbrough and runs over the River Don. Originally built to support four tracks, including track for freight, it was later modified to a three-track set up.
Based on the suspicion that the structure’s river caissons were sinking, VEDA was contracted to devise a process for probing a pier and the depths below. Electromagnetic investigation of the structure failed to produce reliable depression parameters however, adaption of the bridge from four to three tracks had left an original caisson relatively free from track infrastructure.
VEDA decided that boring this structure would give access to the foundational material, which could then be probed for accurate and relevant data. VEDA Engineer Jack Edwards specified the elements and materials for a bespoke steel support platform with six diagonal struts to support a GEO 205 Commachio drilling rig to core the caisson.
The steel 4m by 8m platform was clamped to the caisson.
Once the platform was in place and the coring rig lifted onto the platform using a crane, recovery of samples from below the pier was possible. Samples were also collected using a bore hole method in the vicinity. The results from the coring were provided to NR, who are now in a position to formulate a suitable maintenance or replacement strategy for the bridge.
The design process for the rig platform was completed in four weeks, with the associated onsite work taking two weeks. To ensure the vital protection of the watercourse below the rig platform, a protective membrane was added to its boarding to prevent drilling fluid spillage.
Project Name: Conisbrough Railway Bridge Maintenance
Type of Project: Structural Engineering
Client: Dyer & Butler
Date completed: July, 2016
- Civil Engineering