Comprehensive Bridge Scour Evaluation Methodology

2000 ◽  
Vol 1696 (1) ◽  
pp. 204-208 ◽  
Author(s):  
P. F. Lagasse ◽  
E. V. Richardson ◽  
L. W. Zevenbergen
Keyword(s):  
United States ◽  
Highway Bridges ◽  
The United States ◽  
Annotated Bibliography ◽  
Evaluation Methodology ◽  
Bridge Scour ◽  
State Highway ◽  
Existing Bridges ◽  
State Highway Agencies ◽  
Stream Instability

In the United States, bridge scour technology is discussed primarily in three FHWA publications: Hydraulic Engineering Circular (HEC) 18: Evaluating Scour at Bridges; HEC-2: Stream Stability at Highway Structures; and HEC-23: Bridge Scour and Stream Instability Countermeasures. Together, these documents provide guidance to state highway agencies that is necessary for completing comprehensive scour and stream instability evaluations for the design of new bridges and for repairing existing bridges. Experience has shown that the relationships among the three documents are not always readily apparent, and some scour evaluations have relied primarily on HEC-18. A comprehensive flowchart that illustrates the interrelationship among the three FHWA scour-related documents has been developed. In addition, in 1998, FHWA, TRB, and AASHTO sponsored a scanning review of European practice for bridge scour and stream instability countermeasures. In 1999, ASCE published a compendium of papers on stream stability and scour at highway bridges, and FHWA prepared an annotated bibliography to support revisions to the three HECs. It is anticipated that the flow-chart and the substantial information from the scanning review, the compendium, and the annotated bibliography will be included in the next revisions to HEC-18, HEC-20, and HEC-23. On the basis of information from these sources, a comprehensive approach to bridge scour and stream instability evaluations is outlined, and an overview of planned revisions to the three FHWA HECs is provided.

An evaluation of warranty contracting in the United States of America

2006 ◽  
Vol 33 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Mehmet Emre Bayraktar ◽  
Qingbin Cui ◽  
Makarand Hastak ◽  
Issam Minkarah
Keyword(s):  
United States ◽  
United States Of America ◽  
The United States ◽  
Department Of Transportation ◽  
Construction Costs ◽  
Advantages And Disadvantages ◽  
Contract Administration ◽  
State Highway ◽  
Early Failures ◽  
State Highway Agencies

It is believed that warranty contracting would benefit state highway agencies by improving quality, saving money and time, and encouraging contractors' innovations. However, the challenges associated with warranties could be substantial, including higher costs, early failures, a reduction or even elimination of small contractors from the bidding process, and an increase in contract disputes and litigation. The actual impact of warranty provisions on state Department of Transportation (DOT) projects in the United States of America is still unclear because of limited industry experience. This paper provides a detailed discussion of warranty provisions and the benefits and problems associated with the subject matter. The advantages and disadvantages of warranty provisions are evaluated from the conflicting perspectives of state Departments of Transportation (DOTs), contractors, and surety companies. The future prospects of warranty provisions are established based on the findings of a recent study of warranty provisions and existing literature. Also, several options are proposed that have a strong potential to improve the application of warranties on DOT projects.Key words: warranties, highway construction, innovation, highway maintenance, contract administration, construction costs, construction inspection.

European Practice for Bridge Scour and Stream Instability Countermeasures

2000 ◽  
Vol 1696 (1) ◽  
pp. 236-243 ◽  
Author(s):  
David W. Bryson ◽  
Daniel G. Ghere ◽  
William H. Hulbert
Keyword(s):  
South Carolina ◽  
Filter Design ◽  
Bridge Scour ◽  
State Highway ◽  
The United Kingdom ◽  
River Geomorphology ◽  
River Training ◽  
State Highway Agencies ◽  
Stream Instability ◽  
Design And Construction

FHWA, AASHTO, and TRB sponsored a scanning review of European practice for bridge scour and stream instability countermeasures in October 1998. The review involved a panel of representatives from six state highway agencies (California, Illinois, Maryland, Minnesota, Oregon, and South Carolina), FHWA, two universities, and the private sector. The review included visits to hydraulic research laboratories, highway research institutes, and field sites in four countries—Switzerland, Germany, the Netherlands, and the United Kingdom. Findings during the scanning review can be classified as general observations and observations of specific countermeasures. General observations of European practice include design philosophy, risk analysis, environmental policy, river geomorphology, scour prediction, modeling, and inspection and monitoring. Observations of specific countermeasures include riprap design and construction, filter design and construction, river-training structures, riverbed degradation countermeasures, bioengineering, and flow-altering devices. These observations are contrasted with U.S. practice. The panel’s recommendations for modifying U.S. practice on the basis of the European experience and findings that deserve further evaluation are also presented.

scholarly journals Challenges in Bridge Health Monitoring: A Review

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4336
Author(s):  
Piervincenzo Rizzo ◽  
Alireza Enshaeian
Keyword(s):  
United States ◽  
Health Monitoring ◽  
Highway Bridges ◽  
The United States ◽  
Anomalous Behavior ◽  
Existing Structures ◽  
Bridge Health Monitoring ◽  
Using Data ◽  
The Many ◽  
Major Factors

Bridge health monitoring is increasingly relevant for the maintenance of existing structures or new structures with innovative concepts that require validation of design predictions. In the United States there are more than 600,000 highway bridges. Nearly half of them (46.4%) are rated as fair while about 1 out of 13 (7.6%) is rated in poor condition. As such, the United States is one of those countries in which bridge health monitoring systems are installed in order to complement conventional periodic nondestructive inspections. This paper reviews the challenges associated with bridge health monitoring related to the detection of specific bridge characteristics that may be indicators of anomalous behavior. The methods used to detect loss of stiffness, time-dependent and temperature-dependent deformations, fatigue, corrosion, and scour are discussed. Owing to the extent of the existing scientific literature, this review focuses on systems installed in U.S. bridges over the last 20 years. These are all major factors that contribute to long-term degradation of bridges. Issues related to wireless sensor drifts are discussed as well. The scope of the paper is to help newcomers, practitioners, and researchers at navigating the many methodologies that have been proposed and developed in order to identify damage using data collected from sensors installed in real structures.

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