Arch lifting is necessary when more headroom is required beneath an arch bridge, for example to facilitate overhead line equipment on a newly electrified route. Rather than demolishing the arch and reconstructing it, Freyssinet has developed an innovative method for lifting the masonry arch.
ElevArch® is a patented technique where the arch of a bridge is cut free from its abutments and walls so it can be jacked upwards, enlarging the space beneath before locking into its new position. Freyssinet’s lifting technology allows the arch to be raised while keeping the brickwork and abutments in equilibrium.
In 2014, the RSSB Innovation Railway programme, a collaboration between Network Rail and RSSB, invited participants to enter an ‘Avoidance of Bridge Reconstruction’ competition, in an attempt to find an alternative to demolishing overbridges. It’s estimated that 500 masonry arch bridges in the UK are too low for Network Rail’s electrification programme (more height is needed for the overhead line equipment) and therefore a cost effective solution is required.
Joining forces with renowned masonry arch expert Bill Harvey, Freyssinet explored the feasibility of vertically jacking bridge arches. In 2015, their concept ‘ElevArch®’ was chosen along with four others to advance into phase two of the competition – the full-scale demonstrator.
Finally, following two years of research and development, the world’s first ElevArch® masonry bridge arch lift successfully took place in October 2016. The 161-year-old, 220 tonne masonry arch bridge at Moco Farm in Buckinghamshire was lifted 900mm using ten 50 tonne jacks.
The ElevArch® technique has since won multiple industry awards for innovative concept and environmental benefits. The revolutionary technique minimises intrusion to the rail environment compared to other techniques, significantly reducing cost, time and resources required, which in turn will reduce any potential impact on the environment.
Contact sam.cleobury@freyssinet.co.uk for more information.
ElevArch® – The story so far
Freyssinet to undertake world’s first ElevArch® masonry arch jacking trial – read more.
Freyssinet complete ElevArch® bridge lift trial – read more.
Moco Farm, Buckinghamshire – ElevArch® masonry bridge arch lift trial case study – read more.
Freyssinet wins IStructE award for outstanding value – read more.
ElevArch® wins VINCI Innovation Grand Prize – read more.
Freyssinet’s ElevArch® technique wins Rail Industry Innovation Award – read more.
Freyssinet shortlisted for Structural Awards 2017 – read more.
Tunnel Bore Enlargement
Tunnel bore is used when increased gauge is required for larger rolling stock or where there has been distortion of the tunnel over time due to ground movement. In France, Freyssinet has carried out several bore enlargement schemes for the state railway SNCF. Sequencing the works correctly is vital because cutting into the lining weakens it. Freyssinet’s solution is to cut ribs into the brickwork, then reinforce and concrete them. It then removes the infill panels and replaces with sprayed concrete.