Infrastructure
Repairs and Inspection
Rehabilitation of a structure in general requires considerations of unique methods of inspection and repair. Since the structures have to remain in service while the repairs are done,...
Building Over the Golden Gate
Charles Seim discusses the struggles of the original bridge advocates to garner support for the Golden Gate Bridge, an idea which originally met with a considerable amount of public opposition....
Golden Gate Bridge Improvements
The Golden Gate Bridge, Highway and Transportation District engineer talks about improvements made to the Golden Gate Bridge since opening day. Improvements covered include: wind bracing,...
Historic Bridges: Conflict Ahead
The engineer who deals with historic bridges becomes the focus of controversy in the course of determining the existing condition, predicting remaining useful life, and designing the repair...
Water Jets: Concrete Yes, Tunneling Maybe
High pressure water jets are demolishing concrete from bridge and parking decks, faster and at lower cost than by traditional means. The technique is fast becoming an acceptable option....
Automating Bridge Design
To avoid some of the pitfalls of manual design calculations, Parsons Brinckerhoff Quade & Douglas engineers designing a series of bridges for a $280 million section of the New...
Analysis of Scour Problems at Louisiana Bridges
An ongoing project to automate the monitoring of scour measurements at Louisiana bridge sites is discussed. The data at selected bridges is digitized and put into computer files for analysis....
Modification of Meander Pattern Using Wing Dams
A sharp river bend and a highway bridge together create potentially hazardous conditions for all down-bound barge tows on the Mississippi River at Lansing, Iowa. The tendency of the river...
The Scourge of Scour
Among 86 bridge failures from 1961 to 1976, more were caused by scour than by earthquakes, wind, structural problems, corrosion and accidents combined. Scour is the erosion of a stream...
Redundancy Evaluation of Existing Bridges
The redundancy of an existing bridge can only be correctly assessed by considering the full superstructure as a single entity. Any formulation based on the analysis of bridge components...
Calibration of a Bridge Rating Formula for Overload Permits
This paper proposes a method to calibrate a reliability based load and resistance factor design (LRFD) permit evaluation formulation that will account for the overloaded truck's...
LFRD Bridge Design as Viewed by the Designer
The load and resistance factor design (LFRD) design concept has been resisted by some bridge engineers on the grounds that it represents a reduction of the 'factor of safety'...
Evaluation of Corroded Steel Bridges
In the United States there is a large inventory of corroded steel bridges. The evaluation of these existing bridges is difficult when considering all the uncertainties involved in deterioration....
Multiple Presence Reduction Factors for Bridges
This paper reviews the multiple presence reduction factors specified in the AASHTO and Ontario codes, and provides a method by which these factors can be established in relation to volume...
Steel Plate Girder Alternate I-10/I-17 Interchange
The scope of the Phoenix I-10 Viaduct allowed extensive study for the optimization of this moderate span steel plate girder bridge. The value engineering studies lead to the use of the...
Three Automatically Erected Folding Spans
The U. S. Navy has identified three rapidly erected bridges. Each is capable of spanning 400 feet (120 m) with a 70 ton (63 tonne) live load at mid-span. Each will also fold into a 15...
Queensboro Bridge Inspection and Rehabilitation
An in-depth inspection of the Queensboro Bridge revealed deterioration of certain elements on the lower level of the main bridge. These elements include the outer roadway cantilever brackets,...
Prediction of Deformations Due to Heat Curving
This paper summarizes the state of the art in the thermal deformation techniques. Alternate analytical methods are described. The limitations and accuracy of these models are noted, and...
Rehabilitation of the SF Calawah River Bridge
The failure of a 4-span reinforced concrete bridge in Washington State initiated a study that ultimately led to a unique method of bridge rehabilitation. Severe scour resulted in settlement...
Measures Against Wind-Induced Vibrations of Bridges
The design of very flexible structures, such as long-span steel bridges, are frequently governed by wind-induced vibrations. This paper introduces the present situation of the cable-supported...
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