Composite Plate Girders Research Articles

Prestressed Spliced I-Girders: Tenth Street Viaduct Project, Lincoln, Nebraska

The Tenth Street viaduct project in Lincoln, Nebraska, showcases two unique bridge structures. The first is a pedestrian/bicycle overpass which features spliced, prestressed concrete I-girders, designed and built using a new continuity technique. This structure incorporates level landings for the disabled and a deck heating system. The second structure is a vehicular viaduct. Design of this structure included alternative superstructures - a continuous, composite steel plate girder, and a composite, spliced concrete prestressed girder system made continuous via full-length post-tensioning. This paper presents the various project phases, with an emphasis on the pedestrian/bicycle overpass and the implementation of the new girder continuity technology.

STRENGTH AND STIFFNESS OF DISCRETE U-FRAMES IN COMPOSITE PLATE GIRDERS.

Tests are reported elsewhere on a structure of inverted-U section consisting of twin double-cantilever composite plate girders, restrained laterally by U-frames, each with the reinforced concrete slab acting as the horizontal member. Results are given here of the tests of the connections between this member and the steelwork. These and earlier tests provide the basis for tentative design rules, relating to stiffness, diagonal tension cracking of the slab, and local yielding of the steel top flange. (A)

Closure to “ Optimum Design of Composite Hybrid Plate Girders by Balaur S. Dhillon and Chen‐Hsing Kuo (July, 1991, Vol. 117, No. 7) ”

Closure to “ <i>Optimum Design of Composite Hybrid Plate Girders by Balaur S. Dhillon and Chen‐Hsing Kuo (July, 1991, Vol. 117, No. 7)</i> ”

Discussion of “ Optimum Design of Composite Hybrid Plate Girders by Balaur S. Dhillon and Chen‐Hsing Kuo (July, 1991, Vol. 117, No. 7) ”

Discussion of “ <i>Optimum Design of Composite Hybrid Plate Girders by Balaur S. Dhillon and Chen‐Hsing Kuo (July, 1991, Vol. 117, No. 7)</i> ”

Spliced Segmental Prestressed Concrete 1-Beams for Shelby Creek Bridge

The Shelby Creek Bridge is a five-span, high-level highway bridge nearly 1000 ft (305 m) long over a narrow valley in mountainous eastern Kentucky. Equal length prestressed concrete I-beams were spliced together in a unique design that eliminated costly falsework and provided full-length continuity over end spans of 162 ft 3 in. (49.5 m) and three equal interior spans of 218 ft 6 in. (66.6 m). Stay-in-place, precast, prestressed concrete deck panels eliminated most on-site forming and helped to speed up construction of the deck. The segmental prestressed concrete I-beam design was bid against two alternate steel designs and was $417,000 less than the continuous composite welded plate girder alternate and $2 million less than the originally designed steel delta frame girded bridge.

Optimum Design of Composite Hybrid Plate Girders

A general formulation using the generalized geometric programming (GGP) technique is presented for the optimum design of unstiffened and stiffened composite hybrid plate girders. It is based on the load factor design method of the American Association of State Highway and Transportation Officials standard specification for highway bridges. A mathematical formulation is developed for the optimization of the composite hybrid plate girder problem, using the weight of the girder as the objective function and the section properties and strengths for the problem constraints. The independent and dependent variables are defined for the optimization problem, and the design constraints are formulated in both equality and inequality forms. The nonlinear objective function and the nonlinear design constraints are expressed in suitable form for application of the GGP technique to find the optimum design. A computer program is written in FORTRAN 77 to implement the design procedure, and examples are presented to demonstrate the validity of the mathematical model.

Shear Strength of Composite Plate Girders with Web Cutouts

An experimental investigation of the shear strengths of composite plate girders, with centrally placed rectangular web cutouts, is described. A series of tests is conducted on short‐span girders having conventional welded stud shear connectors, connecting the composite concrete slabs to the top flanges of the plate girders. These tests indicated that it is the tensile or pullout capacity of the connectors that is primarily responsible for sustaining the composite action under predominantly shear loading. Subsequently, a further series of tests is conducted on short‐span girders with bolted tension connectors, designed to offer negligible resistance to horizontal shear forces at the interfaces between the concrete slabs and plate girders, which confirmed the previous conclusion. Both series of tests indicate that if adequate connectors are provided between a plate girder and a composite concrete slab, the shear strength of the composite girder is significantly higher than that of the plate girder alone. A simple analytical model for predicting the shear strengths of composite plate girders is also presented, which shows satisfactory correlation with the test results.

Shear strength of composite plate girders with rectangular web cut-outs

An experimental investigation of the shear strengths of composite plate girders, with rectangular web cut-outs is described. The tests indicate that if adequate tension connectors are provided between the plate girder and composite concrete slab, the shear strength of the composite girder would be significantly higher than that of the plate girder alone. A simple analytical model for predicting the shear strengths of composite plate girders is also presented, which shows satisfactory correlation with the test results.

Plastic Collapse Load of Continuous Composite Plate Girders

Composite beams and girders with a reinforced concrete slab have different moment-curvature characteristics, depending on whether the moment is positive or negative. It is usually assumed for the maximum strength of the negative moment section that the concrete slab does not carry tensile stresses, but the reinforcing steel bars are considered to act compositely with the steel section. In the Load Factor Design (LFD) method of the AASHTO Standard Specifications for Highway Bridges, the maximum strength of laterally braced I-shaped sections is determined based on the provision of compact or noncompact sections. A compact section is defined as a section that can reach the plastic moment and rotate inelastically at this constant plastic moment. Recently (1986), the AASHTO Guide Specification for Alternate Load Factor Design Procedures was published for the design of steel beam bridges using braced compact sections. This procedure was adopted as a logical extension of the existing LFD method and it is based on the Autostress Design (ASD) procedures. The resistance of continuous beam bridges is determined by the plastic-mechanism method. In this method, a considerable amount of plastic rotation is required at the negative moment sections of intermediate supports, and so the concept of an effective plastic moment was applied. The ultimate load was assumed to be reached when a composite section in positive bending reached the plastic moment. The usefulness of this method was confirmed by design examples and loading tests of an actual bridge.

AN OPTIMIZATION METHOD USING SELECTION TECHNIQUES OF ACTIVE CONSTRAINT SURFACES

There are a large number of inequality constraints in a structural optimum design problem, however, an optimum design point is usually located on active constraint surfaces that are equivalent to equality constraint. If we select such equality constraints among the inequality constraints, the inequality constrained problem can be transformed into an equality constrained problem. An optimum point of the new problem that is subjected to the selected equality constraints is obtained by using the Lagrange multiplier technique. In this paper an optimization method in which selection techniques are used is proposed, and a simple example on optimum solutions of composite plate girders is shown.

FATIGUE BEHAVIOR OF CONNECTION PLATE BETWEEN MAIN GIRDER AND CROSS BEAM IN COMPOSITE PLATE GIRDER

Since urban freeway bridges were opened for traffic more than ten years ago, there have been so many reports on the necessity of reparing cracks and deformations. For an example, the cracks at the connection plate between girder and lateral load-distribution cross beam are reported, and also the cracks at the connection plate between girder and sway bracings for composite plate girders. The investigation for the cracks, the establishment of repair and reinforcement method, and the feedback to the design standard specifications are now urged and many arguments are in progress in many places. In this research, we would like to find out one of the effective solutions by fabricating the test girders with the previous design and with present design, investigating the effects of the rigidity of the cross beam upon the fatigue crack and comparing and discussing the proposed structual details.

STUDIES ON FATIGUE DAMAGES BASED ON STRAIN MEASURMENTS OF A HIGHWAY BRIDGE

The strain behavior at the connection plate between main girder and transverse bracing in a simply supported composite plate girder is studied in order to find the causes of fatigue cracks. These cracks occur mainly at the upper end of stiffening plates and rib plates for connection, and propagate into the web plates of main girders. The strains measured in field tests are analyzed and fatigue investigations are carried out using Miner's Law. As the result, it is clear that cracks are initiated by cyclic high stress due to unequal deflection of main girders and deformation of slab plate at the front toe of fillet welds between flange plate and stiffener or rib.

TENSION-FIELD ACTION IN COMPOSITE PLATE GIRDERS.

Keywords BRIAN COLQUHOUN, CONSTRUCTIONAL STEEL RESEARCH AND DEVELO, PMENT ORGANISATION, WARWICK UNIVERSITY TENSION, FIELD, ACTION, COMPOSITE, PLATES, GIRDERS, TESTS, FAILURES, NEGATIVE, MOMENTS, STEEL, WEBS, SLENDER, STIFFENED, INTERACTION, PANELS, SHEAR, CONNECTIONS, SLABS, LIGHT, STEEL, TOP, FLANGES, ULTIMATE, STRENGTH, DESIGN, METHODS, BRIDGES, CODES, PREDICTION, VIADUCTS, RESISTANCE, LONGITUDINAL, STIFFENED, SLENDERNESS, RATIOS, AXIAL, ANCHORAGES, RESEARCH, COMBINED, BENDING, THEORY, SPECIMENS, LOADS, TRANSVERSE, REINFORCEMENT, CONSTRUCTION, INSTRUMENTATION, PLASTICITY, COMBINED, MODIFICATION, STANDARDS, MECHANISMS, REINFORCED, DEFORMATION, FORCES, E... Show All

Optimum Design of Mixed Steel Composite Girders

Steels having a variety of yield points are now available to the construction industry, allowing the designer to choose strength as well as size to meet design requirements. This work is concerned with the use of a variety of steel strengths in continuous, welded, composite plate girder bridges to produce minimum cost structures. The solution which is reported obtains the optimum design of a girder subject to the standard specifications of the American Association of State Highway Officials. Span lengths, material properties, concrete deck dimensions, and cost information on steel types and on splicing operations must be given. The capability selects the optimum combination of web height, flange width, plate thicknesses, and the arrangement of steel types for a continuous girder of constant depth. An iterative scheme is used between the material and splice location selection and the determination of the best web depth and flange width. Results are given for example problems considering seven available steels for the design of a composite plate girder.