History and Development of Steel Railway Bridges - Design of Modern Steel Railway Bridges - page 36

bridge design were the leaders in the development of structural engineering practice. ∗
Evidence of this leadership was the publication, in 1905, of the first general structural
design specification for steel bridges in the United States by AREMA.

1.4.3 M ODERN S TEEL R AILWAY B RIDGE D ESIGN
The basic forms of ordinary steel railway superstructures have not substantially
changed since the turn of the twentieth century. Steel arch, girder, and truss forms
remain commonplace. However, considerable improvements in materials, construc-
tion technology, structural analysis and design, and fabrication technology occurred
during the twentieth century.
The strength, ductility, toughness, corrosion resistance, and weldability of struc-
tural steel have improved substantially since the middle of the twentieth century.
These material enhancements, combined with a greater understanding of hydraulics,
geotechnical, and construction engineering, have enabled the design of economical,
reliable, and safe modern railway bridges.
Modern structural analysis has also enabled considerable progress regarding the
safety and economics of modern railway superstructures. Vast advancements in the
theory of elasticity and structural mechanics were made in the nineteenth century as a
result of railroad expansion. Today, the steel railway bridge engineer can take advan-
tage of modern numerical methods, such as the matrix displacement (or stiffness)
method, to solve difficult and complex structures. These methods of modern struc-
tural analysis may be efficiently applied using digital computers and have evolved into
multipurpose finite element programs capable of linear, nonlinear, static, dynamic
(including seismic), stability, fracture mechanics and other analyses. Furthermore,
modern methods of structural design that facilitate the efficient and safe design of
modern structures have followed from research.
Advances in manufacturing and fabrication technologies have permitted plates,
sections, and members of large and complex dimensions to be fabricated and erected
using superior fastening techniques such as welding and high-strength bolting.
Modern fabrication with computer-controlled machines has produced economical,
expedient, and reliable steel railway superstructures.

REFERENCES
Akesson, B., 2008, Understanding Bridge Collapses , Taylor & Francis, London, UK.
Baker, B., 1862, Long-Span Railway Bridges , Reprint from Original, BiblioBazaar,
Charleston, SC.
Bennett, R. and Skinner, T., 1996, Bridge Failures, Recent and Past Lessons for the Future ,
American Railway Bridge and Building Association, Homewood, IL.
Billington, D.P., 1985, The Tower and the Bridge , Princeton University Press, Princeton.
Chatterjee, S., 1991, The Design of Modern Steel Bridges , BSP Professional Books, Oxford.

∗

The advanced state of steel design and construction knowledge possessed by railway bridge engineers
made them a greatly sought after resource by architects from about 1880 to 1900 during the rebuilding
of Chicago after the Great Fire.