Taking a New Approach (available in Structural Engineering Special Section only)

Mandel, Elliott D.; Tse, Kwong T.; Riddle, James T.; ,

Taking a New Approach (available in Structural Engineering Special Section only)

by Elliott D. Mandel, P.E., (M.ASCE), Principal Structure Engineer; Parsons Transp. Group, Inc., Washington, DC,
Kwong T. Tse, P.E., Sr. Struct. Engr.; Parsons Transp. Group, Inc., Washington, DC,
James T. Riddle, P.E., (A.M.ASCE), Struct. Engr.,; Parsons Transp. Group, Inc., Washington, DC,

Serial Information: Civil Engineering—ASCE, 2000, Vol. 70, Issue 8, Pg. A10-A15

Document Type: Feature article

Abstract:

The first bridge rehabilitation project in Washington, DC to use the AASHTO Load and Resistant Factor Design (LRFD) specification reveals several lessons to be learned from using the newly implemented design approach. The intent of the project is to rehabilitate the nearly 40-year-old southbound 11th Street Bridge in Washington, D.C., to ensure safety and extended service life as well as to serve updated operational needs. The structure is a built-up deck plate-girder bridge with stringers and floor beams. The project involves widening, redecking, and repairing the bridge, as well as eliminating the pin connection details. Construction is to be performed while keeping the bridge in service. An instrumentation program will likely be implemented during the construction in order to monitor the structure and ensure that the actual structural behavior is as predicted by analysis. The LRFD Specification influenced the project's inspection, analysis, and rehabilitation. To ensure that proper judgments were made, the chief inspector was required to have training not only in bridge inspection, but also in the behavior and design of bridges, so any reported distress would be accompanied by the inspectors' on-site judgment of appropriate strength reduction factors to be used for analysis and design.

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