A SPECIAL INSPECTION ON A CHALLENGING SITE

A challenging site, with a 1980’s bridge, on the coast, carrying a duelled A-road across a steeply sloping site which variously included a dis-used quarry, a deeply incised stream, a mainline railway, and a national cycleway. The Inspection required, i.e. a feasibility study for a refurbishment scheme, including bearings, which dictated access all areas, with site conditions requiring a combination of MEWPs (underbridge unit and stick boom), scaffold towers and ladders. Some road and rail possessions were needed, with both dayshift and nightshift working.? Duration on site 15days.

The structure comprised an eight-span viaduct, with in-situ cast reinforced concrete piers and crosshead beams, with concrete bearing plinths, which supported a superstructure constructed primarily of longitudinal steel beams, with an in-situ cast, reinforced concrete deck.

Our brief was to undertake a Special Inspection, to put together a feasibility Report for a comprehensive refurbishment.? The Inspection included a full, close-quarters Visual Inspection, including the bridge bearings, with hammer testing to identify, record onto drawings and schedule all defects for repair, with diagnostic investigations of both concrete material condition and reinforcement corrosion condition.

A total of 260 large-scale defects were identified, comprising cracking and surface spalling associated with corrosion of the reinforcement. In addition, there were numerous large previous repairs, installed over 10years prior, using a conventional strategy with no corrosion control.? Many repairs were found to have failed.

When the going gets tough but you need a thorough Job done, call CRL Surveys Limited