Page 153 - Bridge and Highway Structure Rehabilitation and Repair

128 SECTION 1 ADMINISTRATIVE ISSUES

Table 3.14 Risk assessment based on probability.
Probability
Occurring at Occurring at
Hazard Severity Regular Intervals Very Likely Irregular Intervals Not Likely Improbable
Bridge on verge of Risk reduction required Risk reduction Risk reduction Optional risk No risk reduction
collapse required required reduction
Bridge condition critical Risk reduction required Risk reduction Optional risk No risk reduction No risk reduction
required reduction

Marginal damage Optional risk reduction Optional No risk No risk reduction No risk reduction
Risk reduction
Minor damage No risk reduction No risk reduction No risk reduction No risk reduction No risk reduction

Earth has not anything to show more fair,
When engineers endeavor to take good care!
With due apologies to the poet, the second line is added here to underline the importance
of maintenance.
To summarize, nature does not forgive any error in planning, and a little hindsight would
help. Failures are, however, the pillars to success.

BIBLIOGRAPHY
Analysis of Recent Bridge Failures in the United States
Briaud, Jean-Louis, “Failure of Bridges,” American Society of Civil Engineers, 2003.
Brauer, Roger L., Safety and Health for Engineers, 2nd Edition, John Wiley & Sons, Inc., Hoboken, NJ,
2006.
Petroski, Henry, To Engineer is Human: The Role of Failure in Successful Design, Vintage Books, New
York, NY, 1992.

Additional References
Abram, J., Nick Nicholson, E. B. Williamson and K. A. Marchand, “Regular Inspection of Transporta-
tion Facilities is Critical To Public Safety,” 2006 Structures Conference, American Society of Civil
Engineers, St. Louis, MO, May 2006.
Akesson, Björn, Understanding Bridge Collapses, Taylor and Francis Group, London, 2008.
Baird, J., R. A. Nolte and D. Selke, “Blast Mitigation for Structures,” 2006 Structures Conference, American
Society of Civil Engineers, St. Louis, MO, May 2006.
Biezma, M. V. and F. Schanack, “Collapse of Steel Bridges,” Journal of Constructed Facilities, Vol. 21,
No. 5, pp. 398–405, September/October 2007.
Billah, K. Y. and R. H. Scanlan, “Resonance, Tacoma Narrows Bridge Failure, and Undergraduate Physics
Textbooks,” American Journal of Physics, Vol. 59, No. 2, February 1991.
Bureau of Transportation Statistics, “National Transportation Statistics,” ASCE Proceedings, Washington,
DC, 2005.
Chajes, Michael, Dennis Mertz, Spencer Quiel, Harry Roecker and John Milius, “Steel Girder Fracture
on Delaware’s I-95 Bridge Over the Brandywine River,” 2005 Structures Congress and Forensic
Engineering Symposium, American Society of Civil Engineers, New York, NY, April 2005.
Chopra, A. K. and C. Chintanapakdee, “Accuracy of Response Spectrum Estimates of Structural Response
to Near-Field Earthquake Ground Motions: Preliminary Results,” Structural Engineering World Con-
gress, Elsevier Science Ltd., Oxford, England, 1998.