More extreme weather is affecting key infrastructure around the UK, and monitoring difficult to access structures such as bridges needs a specialised approach. NCE reports.
Materials used to build bridges are constantly affected by fatigue and general wear and tear from traffic load.
These effects may also be aggravated by defects in materials that react to chemicals, increased loads and exposure to external factors such as adverse climatic conditions that are becoming more extreme and frequent.
Expansion, contraction and load transfer components like bridge bearings will, in time, all require rehabilitation or replacement and are often in need of closer monitoring, especially on a stock of ageing infrastructure.
Bridge bearings can be a real challenge and be very difficult to access and inspect.
Engineering consultant Xeiad (formerly Bridgezone) specialises in getting access to hard to reach parts of structures.
The company regularly carries out complex inspections and assessments requiring the simultaneous application of engineering expertise and rope access skills to gather critical technical data from otherwise inaccessible structures of all sizes.
Xeiad’s recent analysis of precision measurement data about sliding plate, elastomeric and mechanical, rocker and roller, pot and or restraining bearings, has revealed that the rate of deterioration of bearings on some structures has accelerated in the UK.
The analysis suggests that deterioration can be observed on many constituent parts of bearings when present including sliding plates, bearing surfaces, masonry or grout plinths and/or anchorages.
Deterioration appears to be caused in the most part by the effects of weather, poor drainage control/maintenance and in some cases, overloading.
Structures that appear to be most affected were constructed from the late 1960s to the mid 1980s and have suffered from a chronic lack of investment and maintenance.
Although a vital part of the serviceability and safety of bridges, bearings can be dangerously and easily overlooked by cash strapped asset owners and managers,the stakes are high and risks are compounded by our rapidly ageing infrastructure and the lack of government investment over the past 20 years.
Although budgets allocated to local government and specialist agencies are still suffering from a lack of funding, Xeiad is witnessing a higher level of demand for its services in this area. Xeiad says it is being asked to conduct increasingly detailed precision inspections and assessments requiring a greater degree of engineering input, while inspection regimes are being upgraded.