Bridge Design and Evaluation: LRFD and LRFR
Gongkang Fu
Language: English
Pages: 456
ISBN: 0470422254
Format: PDF / Kindle (mobi) / ePub
A succinct, real-world approach to complete bridge system design and evaluation
Load and Resistance Factor Design (LRFD) and Load and Resistance Factor Rating (LRFR) are design and evaluation methods that have replaced or offered alternatives to other traditional methods as the new standards for designing and load-rating U.S. highway bridges. Bridge Design and Evaluation covers complete bridge systems (substructure and superstructure) in one succinct, manageable package. It presents real-world bridge examples demonstrating both their design and evaluation using LRFD and LRFR. Designed for a 3- to 4-credit undergraduate or graduate-level course, it presents the fundamentals of the topic without expanding needlessly into advanced or specialized topics.
Important features include:
- Exclusive focus on LRFD and LRFR
- Hundreds of photographs and figures of real bridges to connect the theoretical with the practical
- Design and evaluation examples from real bridges including actual bridge plans and drawings and design methodologies
- Numerous exercise problems
- Specific design for a 3- to 4-credit course at the undergraduate or graduate level
- The only bridge engineering textbook to cover the important topics of bridge evaluation and rating
Bridge Design and Evaluation is the most up-to-date and inclusive introduction available for students in civil engineering specializing in structural and transportation engineering.
for a structural component of the bridge, such as the shear at the support of a girder or fatigue limit state for a weld. While the load effect Q is not modeled as a normal variable, the reliability index definition in Eqs. 2.4-12 and 2.4-13 was used in the calibration calculation, according to the method of Rackwitz and Fiessler (1978). According to Nowak (1999), calibration of the AASHTO LRFD specifications was performed using the following four steps: (1) Selection of typical bridge types and
AASHTO specifications also suggest that the bridge owner may require alternative contract plans for bidding competitively. Of course, alternative plans are required to be of equal safety, serviceability, and aesthetic value. More specifically, movable bridges over navigable waterways should be avoided to the extent feasible, according to the AASHTO specifications. Where movable bridges are proposed, at least one fixed bridge alternative should be included for economic comparisons. 2.8 Aesthetics
specifications. Another alternative way of using this book is to teach only its bridge analysis and the related examples or portions of the examples. It can be part of a structural analysis course or an independent course at either undergraduate or graduate level. The examples included in this book can be used without referring to the text. Such use can be particularly convenient for review after a level of understanding of the relevant text material is established. Therefore, they may also serve
offices: the reinforced concrete deck designed in Examples 4.1, 4.3, and 4.4 plus the steel plate girders designed in Examples 4.9 to 4.11 plus the shear studs designed in Example 4.8 plus the abutment designed in Examples 6.1 to 6.4. Examples 7.1 and 7.2 then provide the bridge’s superstructure member load rating. Of course, the deck design in Example 4.1 may be replaced by another deck design in Example 4.2. Furthermore, the superstructure steel beams in Examples 4.9 to 4.11 may be replaced by
below). ❑ DF for moment for two or more lanes loaded: 4.6.2.2 DFmoment interior 2 = 0.075 + S 9.5 0.6 S L 0.2 Kg 12 L t 3 0.1 (4.7-2) Between the DF values for one lane and multiple lanes loaded with the multiple presence factor already included, whichever is larger will control the capacity of the beam. This concept is applicable in designing 4.7 Design of Steel I Beams shear and other beams. Again, with the bridge owner’s concurrence, Kg / 12 L ts3 0.1 = 1.02 is allowed in the