There was structural damage, including cracks, on the pillars of the British-era bridge
Train services were resumed on the restored railway bridge (No: 299) across Ponnai river near Tiruvalam railway station in Vellore, with a restricted speed limit of 30 kmph.
Railway officials said that there was structural damage, including cracks, on the 38th and 39th brick and mortar pillars of the British-era bridge, which connects Tiruvalam and Mukundarayapuram railway stations on the Arakkonam — Katpadi section of the Southern Railway.
The damage was found on December 23 (last Thursday) by a gangman. Since then, workers toiled round-the-clock to restore the rail line, with a trial run having been undertaken using a goods train and a loco engine on the bridge before the rail bridge section was certified fit for traffic on Sunday night. Despite the resumption of train services on the track, speed limits have been specified due to structural weakness in the bridge, built in 1865. "The supporting steel beams around the damaged pillars are a stop-gap measure. A new bridge alongside the existing one will be built soon," a railway official said.
Some of the major restoration efforts undertaken by the engineering team of Chennai division on the bridge include building a cofferdam; pressure grouting into the cracks to avoid further extension; boulder pitching around the pier to prevent further scouring; and concrete work with special grouting along the affected pier.
A team of 850 railway workers, including contract labourers, were roped in for the restoration work that was monitored by Ganesh, Divisional Railway Manager (DRM – Chennai), and a technical team from the Structural Engineering Research Center (SERC-CSIR). The damaged brick and mortar pillars were supported with 14 tonnes of rolled steel beams with 14 cubic metres of wooden columns and planks on the river bed.
The restored bridge was used by trains from Chennai proceeding towards Katpadi, with trains going towards Chennai using the newly-built railway bridge.
These arch-like pillars, railway officials said, have a lifespan of 60 years.
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