Distortion-induced Fatigue in Multi-girder Steel Bridges

Distortion-induced Fatigue in Multi-girder Steel Bridges

Author: Dmitri Jajich

Publisher:

Published: 2000

Total Pages: 296

ISBN-13:

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This report summarizes the findings of a project with the following goals: to implement a field instrumentation and monitoring program for a typical multi-girder steel bridge on skew supports that may be susceptible to web-gap distortion; to assess the frequency and magnitude of the distortional fatigue stresses at the web-stiffener connections; and to evaluate the impact of these stresses on fatigue life. Measurements from 12 independent strain gauges were continuously monitored and recorded for more than three months on Minnesota Department of Transportation (Mn/DOT) bridge #27734. Truck loading tests also were conducted. Predicted web-gap fatigue life based on the long-term monitoring data from Mn/DOT bridge #27734 ranges from 45 to 75 years. Comparison of web-gap stresses with primary design stresses reveals that web-gap distortional stresses are comparatively high. The report also highlights a detailed finite element study to better understand the web-gap stress mechanism and to compare experimental results with theoretical predictions. Study results have important implications for investigators of distortion-induced web-gap fatigue. They indicate that the actual stress at the so-called hotspot may be as much as twice the stress measured at the strain gauge. The report includes a method for estimating girder deflections and web-gap stress.


Feasibility Study for a Freeway Corridor Infrastructure Health Monitoring (HM) Instrumentation Testbed

Feasibility Study for a Freeway Corridor Infrastructure Health Monitoring (HM) Instrumentation Testbed

Author:

Publisher:

Published: 2012

Total Pages: 208

ISBN-13:

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This research report discusses the planning necessary for the proper development, acquisition, installation, and maintenance of an effective health monitoring network for transportation infrastructure systems. A comprehensive literature search was conducted, and the materials were compiled into a database, reviewed, and synthesized. Data elements vital for maintaining safe and functional transportation infrastructures were identified and discussed for bridge structures, pavements, and geotechnical structures. Moreover, the steps necessary for planning an instrumentation system for a particular structure are presented. Sample design plans for the transportation infrastructure systems that are typically constructed in Wisconsin were obtained from WisDOT, and suggested instrumentation plans were developed for these transportation systems. One of the objectives of the research project is to identify urban freeway construction projects that could efficiently serve as hosts for an infrastructure health monitoring (IHM) instrumentation testbed. Major current and near-future construction projects in Wisconsin were identified and critically evaluated to identify a candidate project to host the IHM testbed. Among the candidates, the Zoo Interchange reconstruction project is recommended for hosting the infrastructure health monitoring testbed. Cost estimates based on current market prices are provided for the instrumentation plans developed for IHM of bridge structures, pavements, and geotechnical structures. To provide an example of using IHM data in applications, archived data from the Marquette Interchange instrumentation project was used to develop vehicle wander patterns and load spectra data, both in the form needed to conduct a mechanistic appraisal of the pavement structure using the DARWin ME software. The research team designed and conducted an IHM survey of state highway agencies in the U.S. and Canada. The survey showed that 46 percent of state DOTs have implemented health monitoring applications for transportation infrastructure. The survey also identified the impediments facing state DOTs in implementing IHM systems.


Diagnostic and Proof Load Tests on Bridges

Diagnostic and Proof Load Tests on Bridges

Author: Fikret Necati Catbas

Publisher: Frontiers Media SA

Published: 2020-12-11

Total Pages: 212

ISBN-13: 2889662128

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This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.