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Showing 1 to 20 of 28 for “"Steel bridges"”.
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The design of prestressed composite steel bridges
… structures particularly suited for long span bridges. The slab-and-stringer bridge is one of the most common types in highway construction. Such a bridge is composed of two principal load-carrying elements: the steel beams which transfer the loads in the direction along the bridge axis, and …
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Experimental and numerical investigation of modular steel bridges
… into the structural performance of modular bridges through full-scale experimental testing and advanced finite element modeling. The experimental program included full-scale testing of two types of truss panels commonly used in modular bridge construction under ultimate load conditions. It …
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Effects of thermal loads on Texas steel bridges
The effects of thermal loads on steel bridges are not well understood. Although thermal effects are discussed in the AASHTO specifications, the appropriateness of the recommended thermal gradients is questionable. Thermal effects on the bridges can impact the design of the steel superstructure, the …
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Custom-Engineered and Additively Manufactured Components for Strengthening Steel Bridges
… a primary deterioration mechanism in aging steel bridge infrastructure, reducing stifness and load-carrying capacity. Current inspection practices are largely qualitative, and conventional repair methods often restore nominal area without fully addressing irregular corrosion geometry. This …
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Comparative Study of LRFR and LFR Methods of Rating for Missouri Steel Bridges
… is a method used to check on the ability of bridges to carry a given live load. Bridge rating is important to ensuring public safety in that it helps the concerned agencies to enforce weight restriction on heavy vehicles to safeguard the structures from failure. Before the bridge is rated, …
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FEA methodology for system-level redundancy evaluation: Application to non-composite steel bridges
<p>Currently, all steel bridges with members designated as Fracture Critical Members (FCMs) are required to undergo hands-on inspections every 24 months. A FCM is a primary steel tension member (or portion of) which failure results in collapse or loss of serviceability of a bridge. However, …
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Distributed Fibre Optic Sensing to Assess Support Reactions and Behaviour of Composite Steel Bridges
… beam, model bridge, and field load tests. Five steel beams were instrumented with fibre optic sensors and loaded in simply supported and continuous beam configurations. Disturbed regions in DFOS strain measurements were found to extend a distance equal to the depth of the section from supports …
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Brace Effectiveness of Cross-frame Layout and Connection Design on Skewed Steel Bridges During Construction
… Transportation Officials (AASHTO) provisions for bridges with skew angle greater than 20 degrees are based on the assumption that cross-frames are oriented perpendicular to the girder line. There is a potentially significant discrepancy between assumptions implicit in the AASHTO Specifications and …
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Static push-out tests and finite element studies on larger diameter shear studs for composite steel bridges
Efficient steel bridge girder design makes use of composite action between the concrete bridge deck and the steel girders. The critical link between the deck and the girders are shear studs welded to the girder top flange. The most commonly used shear studs have a 7/8-inch diameter and are welded …
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STANDARDS TO CONTROL FRACTURE IN STEEL BRIDGES THROUGH THE USE OF HIGH-TOUGHNESS STEEL AND RATIONAL INSPECTION INTERVALS
Non-redundant steel bridge systems have been used for major bridges in the United States since the late 1800’s. Designers recognized the inherent structural efficiency and economy associated with two-girder and truss systems. Unfortunately, early knowledge was limited regarding fatigue, fracture, …
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Multiaxial Fatigue Life Extension of Steel Elements Using Shape-Memory Alloy/Carbon Fiber-Reinforced Polymer (SMA/CFRP) Patch
… is a primary factor hindering the performance of steel bridges. Without alternative load-paths, fatigue failure of a member can lead to sudden and catastrophic collapse of the entire structure. There are currently more than 170,000 steel bridges containing fatigue-sensitive details in service …
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BOND BEHAVIOR BETWEEN STEEL AND HIGH MODULUS CFRP PLATES AT MODERATLEY ELEVATED TEMPERATURES
… up to 50oC, on the bond behavior of steel beams strengthened with externally bonded carbon fiber reinforced polymer (CFRP) plates. In the first phase of the research, five steel-CFRP bonded double-lap shear coupons were tested at different temperatures to characterize the bond …
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Pattern recognition techniques applied to rust classification in steel structures
The life and performance of steel structure depends directly upon the steel surface preparation. The restoration of steel structure such as steel bridges, ships and storage tanks is due mainly to the use of manual surface inspection methods accompanied by surface preparation technologies. It …
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Experimental assessment of cracked steel beams under mechanical loading and elevated temperatures
… arson, and in some cases wildfires. The affected bridges are mostly fabricated from steel, concrete, and temper. The problem of bridge fire is further aggravated by the presence of fatigue cracks in steel bridges. Various experimental and numerical studies have been conducted to evaluate the …
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Mag Feet : a robotic device for the inspection of steel bridge structures
The aging of America's steel bridges presents many challenges. Undetected cracks and corrosion can eventually lead to catastrophic failure. Due to the difficulties with inspecting existing bridges the use of mobile robots for steel bridge inspection has become an important area of research. This …
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Effects of Surface Condition on the Fatigue Behavior of CFRP-to-Steel Joints
The strengthening of steel bridges using CFRP laminates has become a commonly used technique because of its numerous advantages compared to conventional repairs which involve welding or bolting of new steel plates. These structures will experience some sort of irregular cyclic loading during their …
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A Mathematical Framework for Analysis and Design of MagneticClimbing Mobile Robots
… atypical environments like those found on steel bridges, turbines, and silos are currently being researched and developed globally through funding from a range of governments. Improvements to robots of this type are highly desirable because efficient and detailed inspection of …
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Repair of Steel Bridge Girders Damaged by Distortion-Induced Fatigue
… fatigue as the leading cause of cracks in steel bridges built prior to the mid-1980s. Experimental and computer simulations of 914-mm (36-in.) deep girder-cross frame subassemblies subjected to cyclic loading were carried out to study the effects of distortion-induced fatigue and to …
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Development of a Field Monitoring System for the Northside Drive Bridge
… a system for real-time structural monitoring of bridges, ultimately offering a reliable method to accurately estimate a bridge’s remaining fatigue life. Standard procedures exist to calculate the remaining fatigue life of steel bridges. However, such procedures rely on conservative estimates of …
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Bridge maintenance to enhance corrosion resistance and performance of steel girder bridges
… on the condition of the various components. Bridges are fundamental elements of a highway system, representing an important investment and a strategic link that facilitates the transport of persons and goods. The cost to rehabilitate or replace a highway bridge represents an important …
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