Editor’s Note – July 2009
Bruce E. Peterson
Editor
Papers In This Issue
The July 2009 issue of the ASCE Journal of Bridge Engineering begins with a paper on the
variable-amplitude fatigue strength of structural steel details. “Variable-Amplitude Fatigue
Strength of Structural Steel Bridge Details: Review and Simplified Model” by Albrecht and
Lenwari reviews eight previous studies on the variable-amplitude fatigue strength structural steel
details. The review found that the variable-amplitude data correlated well with the constantamplitude data when the variable-amplitude data is plotted in terms of an equivalent root-meancube stress range. Based on the results the authors suggest that the current AASHTO equations
be replaced with a single equation similar to the equation used to predict the fatigue crack growth
rate in metals as the simplified model more accurately predicts the fatigue life near the variable
amplitude fatigue limit.
Barth and Roberts in “Flexural Capacity of Compact Composite I-Girders In Positive Bending”
present an assessment of the behavior of composite positive bending specimens. Recent
experimental tests coupled with finite element analysis and mechanistic evaluations of the cross
section flexural capacity suggest that larger capacities could be achieved from AASHTO’s
equations. A less conservative design moment capacity expression developed from this
assessment is provided.
The third paper in this issue of the journal is “Load Rating and Reliability Analysis of an Aerial
Guideway Structure for Condition Assessment” by Shmerling and Catbas. The purpose of the
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Editor’s Note – July 2009
paper is to present a study of the structural behavior and capacity used up in an existing
guideway structural system which has been in service for about thirty five years. The critical
parameters were material properties, prestress losses, boundary condition, and continuity
conditions. The information from their work can be utilized for improved inspection and for the
development of long term structural monitoring.
Liu, Frangopol, and Kim in “Bridge Safety Evaluation Based on Monitored Live Load Effects”
present a new approach to evaluating the safety of existing bridges based on monitored structural
responses and component conditions. A limit state equation is developed for the measured strain
data from the monitoring system. With the addition of new concepts, the condition function and
the performance function, the monitoring information is integrated into the structural safety
evaluation. The result is a life-cycle cost-oriented and reliability-based infrastructure
management system using structural monitoring.
The fifth paper is by Yan and Chang. In “Vulnerability Assessment of Cable-Stayed Bridges in
Probabilistic Domain” the authors propose a two step assessment methodology for cable-stayed
bridges. Based on a hypothetical single-tower cable-stayed bridge the authors show that the
proposed method provides a quantitative tool for analyzing the vulnerability performance of this
type of bridge as a result of a terrorist event.
“3D Coordinating Relations Between Steel Cables and Concrete of Prestressed Concrete Beam
Bridges” by He, Fan, Zhu, and Ye present a method to address the interaction between steel
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Editor’s Note – July 2009
cables and concrete in curved prestressed concrete bridges. Their method utilizes the grillage
structure finite-element method.
The final paper in this issue of the journal is another historical paper by Griggs. “Thomas C.
Clarke, Bridge Builder” is about one of the leading engineers in North America who worked on
railroads, waterways, buildings, and bridges. He was a leader in the formation and running of
several major bridge design and construction companies, served ASCE for many years beginning
as a director in 1870 and was elected President of the Society for 1896-1897.
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