Bridge Engineering. Classifications, Design Loading, and Analysis Methods

WEIWEI LIN, TERUHIKO YODA

Preference :

A bridge is a construction made for carrying the road traffic or other moving loads in order to pass through an obstacle or other constructions. The required passage may be for pedestrians, a road, a railway, a canal, a pipeline, etc. Obstacle can be rivers, valleys, sea channels, and other constructions, such as bridges themselves, buildings, railways, or roads. The covered bridge at Cambridge in Fig. 1.1 and a flyover bridge at Osaka in Fig. 1.2 are also typical bridges according to above definition. Bridges are important structures in modern highway and railway transportation systems, and generally serving as “lifelines” in the social infrastructure systems. Bridge engineering is a field of engineering (particularly a significant branch of structural engineering) dealing with the surveying, plan, design, analysis, construction, management, and maintenance of bridges that support or resist loads. This variety of disciplines requires knowledge of the science and engineering of natural and man-made materials, composites, metallurgy, structural mechanics, statics, dynamics, statistics, probability theory, hydraulics, and soil science, among other topics.

The bridge structures are important components in highway, railway, and urban roads and play important roles in the economy, politics, culture, as well as national defense. Especially for medium span and larger span bridges, they are generally served as “lifeline” engineering due to their vital functions in the transportation network. Therefore, the bridge structures should be carefully planned and designed before the construction. The bridge design process, bridge design philosophy will be discussed in this chapter. A brief diagram showing the bridge planning and design process is shown in Fig. 2.1. In bridge design survey, planning, and design, the structural safety, serviceability, economic efficiency constructability, feasibility in structural maintenance, environmental impact, etc., should be considered to propose an appropriate bridge location and suitable structural type.