ICE - Institution of Civil Engineers - Virtual Library

The implementation of structural Eurocodes is the biggest ever change to codified structural design in the UK. The new standards will replace British Standards for structural design, and will be implemented by the Highways Agency (‘the Agency’) for bridge design over the next four years. The Agency is committed to using Eurocodes for the design of all highway structures and will introduce the Eurocodes for all new procurement at an appropriate time after the respective UK National Annexes are published. This briefing note discusses the implementation aspects in more detail, outlining the Agency's Eurocodes strategy. This includes the effects on the Design Manual for Roads and Bridges and the design studies that have been carried out to ensure highway bridges continue to be designed safely and economically following implementation of the Eurocodes.

Trials conducted on the London Millennium Footbridge in 2000 monitored movements using three GPS receivers. After initial processing, the results gave plausible vertical and lateral (sideways) displacements, but also described implausible longitudinal movements along the axis of the bridge. Digital signal processing techniques applied to the data are reported. Due to the satellite constellation in the UK, a large void exists from the zenith to the horizon in a northerly direction. This lack of GPS satellites results in poor satellite geometry in the north-south direction, and hence poor north-south precision, explaining the unsatisfactory element of the Millennium Bridge results. More importantly a technique to overcome the issues is described. Notwithstanding this, the lateral vibration frequencies obtained from the GPS data agree extremely well with those found in the modal surveys carried out by Arup, even when displacement amplitudes are small.

The embodied energy and carbon dioxide emissions from the use of construction materials are among the concerns engineers must consider when planning, designing and constructing a bridge. Previous studies have been carried out on building structures to assess both the energy consumed and the CO₂ emissions in their construction and use but less information is available to bridge designers. This paper outlines the range of embodied energy and CO₂ emissions for materials commonly used in bridges and the variability of these values is discussed. A study is carried out for a moderate length river bridge of energy use and CO₂ emission during construction. A number of different bridge forms and materials are considered. The primary forms are girder, tied arch and cable stayed. Three broad material groups were investigated, namely concrete, steel and steel–concrete composite. The study also estimates the continuing CO₂ emission throughout the life of the structure from maintenance and repairs. From the study a number of broad trends are discussed and some design guidance offered for those wishing to provide more environmentally responsible bridges

The self-anchored suspension bridge provides a competitive solution for bridges with short or moderate spans. This paper introduces some key techniques used in three concrete, self-anchored suspension bridges in China: GoldenBay Bridge, LanQi Bridge and WanXin Bridge. GoldenBay Bridge was the first concrete self-anchored suspension bridge in China. WanXin Bridge has a main span of 160 m. The appropriate structural forms were designed to take account of their different geographic positions, surrounding environments and functions. In the WanXin Bridge, two sliding saddles and one fixed saddle are set at each end of the main girder. The cables are made of a continuous galvanised steel rope passing over all saddles, and the two main cables form a closed loop. It was the first time that the practice of using a looped main cable had been utilised in China. Currently, the WanXin Bridge has the longest span of all concrete, self-anchored suspension bridges in the world. The final part of the paper describes the model investigation, developed to understand the basic structural behaviour of the WanXin Bridge.