Flood damage to an unclassified road requiring repair and strengthening of its single span natural stone arch
The client: Merthyr Tydfil County Borough Council
The bridge is a single span segmental stone arch with a clear square span of 3.5m. It comprises a natural stone arch and abutments on spread foundations and carries the unclassified Pentwyn Deintyr road over the Nant Mafon Brook.
The flood damage problem
The bridge had suffered from severe flood damage. The spandrel walls had been severely damaged and a large bulge had formed in the barrel of the arch.
The Goldhawk solution
Following analysis using ASSARC assessment a repair scheme was devised using MARSYS. The fill over the barrel was removed and the bulging area of the barrel was jacked back into shape. The MARS System was installed and stainless steel anchors were additionally installed through the barrel into a new reinforced concrete backing. Works were completed within the scheduled five weeks, including repairs to the parapet walls.
Flood damage to the unclassified road bridge
Extensive flood damage caused the spandrel walls to collapse
A bulge in the barrel
A large bulge had formed in the barrel of the arch
Jacking the barrel
The Goldhawk team removed the fill over the barrel and jacked the bulging arch back into shape.
The MARS system
Additional stainless steel anchors were installed alongside the MARS system into new reinforced concrete backing.
Finishing and reopening the road
The repairs and strengthening left the visual appearance virtually unaltered and allowed the bridge to be opened to unrestricted two way traffic.