The claim relates to problems on a stretch of the London to Holyhead trunk road between Ty Nant and Dinmael in Clywd, North Wales, which had to be closed for more than a year because of the danger of rock falls.
The problems began after improvement works to the road by Miller Civil Engineering (now Morgan Est) as part of a ВЈ4.1m contract carried out between 1994 and 1997.
The works involved building a 620m stretch of straight road through a hillside, creating 30m-high cuttings in the rock, to be stabilised by rock anchorages.
In a writ lodged at the Technology and Construction Court, the Welsh Ministers claim a 2002 inspection found that two rock anchorages had corroded.ADVERTISEMENT
Further investigations showed that a number of anchorages and face plates were deteriorating, while some had corroded to such an extent that they had lost all strength.
The road was closed in May 2006 for remedial works following a risk assessment. It was reopened in July 2007.
The Welsh Ministers allege that Miller breached its contract and claim that a number of factors contributed to the anchoragesвЂ™ failure, which include:The omission of caps over the anchor heads which allowed protective grease to escape; The faceplate on the majority of rock anchorages being cut so short that they were less than the 300mm required by the manufacturerвЂ™s detail; Damage to the rubber seal in many of the rock anchorages.
The Welsh Ministers are the statutory successors to the Secretary of State for Wales, the highways authority for motorway and trunk road construction in Wales when the contract was awarded.