Summary bridges

• A brief historical review of bridges demonstrates the importance of these structures and the developments which have led to increasingly long spans.
• Because of its high strength-weight ratio steel is a very popular material for bridge construction
• There are three basic structural systems employed in bridge construction – beams, hanging cables and arches - and a number of hybrid variations.
• Bridge construction must consider a number of technological issues including vibration effects from wind loads, corrosion and maintenance.
• Construction details at supports – referred to as bearings – require special attention.
• A variety of erection methods can be used depending on particular circumstances.
• There is an increasing recognition of the importance of the aesthetics of bridge design