Bridge Design and Evaluation LRFD and LRFR

Gongkang Fu

Preference :

Human beings have been constructing bridges for about four thousand years. The oldest and still existing bridge in the world is perhaps the Zhaozhou Bridge in Hebei Province in China, originally constructed approximately in A.D. 600. However, bridge design and construction then may not be considered bridge engineering practice by today’s definition. Instead, work was done based more on experience as opposed to quantitative planning as done now. Bridge engineering today uses calculus-based analysis and detailed planning. Materials used in bridge construction have also changed noticeably through a good number of years, from mainly natural materials such as stones and wood than to mainly man-made materials such as steel and Portland cement concrete today. Due to great improvement in the strength and production quality control of these materials, bridge components have become smaller, thinner, skinnier, and lighter to reduce self-weight and be more economical.