Steel Deck Plate Research Articles

Structural Behaviour of Surfacings on Steel Orthotropic Decks and Considerations for Practical Design

Surfacings on steel orthotropic decks act compositely with the steel deck plate and must be regarded as an integral part of the structural deck system. Surfacing materials are generally visco-elastic to plastic and behave elastically only at low temperatures. Elastic moduli of most surfacings strongly depend on temperature. In semi-plastic condition flexural strain distribution through the surfacing thickness becomes non-linear. With a soft bonding layer, shear slip occurs at the interface. Surfacings contribute substantially to deck rigidity and are subject to considerable stresses due to local bending of the steel deck plate. Locations and causes of critical deck plate stresses affecting surfacing performance are discussed. Characteristic properties of the two basic surfacing categories, the bituminous and the polymer materials, are presented with examples of their applications on orthotropic decks. It is suggested that satisfactory performance of surfacings should be achieved by more stringent limitations of the local deck flexibility.

Development of a New Structural Model with Prism and Strip Elements for Pavements on Steel Bridge Decks

A new structural model for pavements on steel bridge decks (SLPE) is developed. In this model, a prism element and a strip element represent the pavement and steel bridge deck, respectively. A newly developed link element models the insulation layer that bonds the pavement to the steel deck plate. The SLPE model is verified by calculations that simulate a simply supported square plate and an actual pavement on a bridge deck. Furthermore, the model is expanded to deal with dynamic problems that consider the viscosity of asphalt materials.

DEVELOPMENT OF A STRUCTURAL MODEL WITH PRISM ELEMENT AND STRIP ELEMENT FOR PAVEMENT ON STEEL PLATE DECK

The structural model for pavements on steel plate deck should be able to deal with structure of the steel plate deck as well as pavement structure. This paper presents a structural model using the strip element and prism element. In this model, the steel plate deck is modeled by the strip element and the pavement is divided with the prism element. The strip element and the prism element are connected with a link element. This model is able to analyse the local deformation of pavement, particularly with low stiffness. The validity of the model was verified with numerical examples and comparisons with the experimental results obtained on an actual pavement on a steel plate deck.

STUDY ON LONGITUDINAL SURFACE CRACK IN PAVEMENT ON STEELPLATE DECK

A condition survey was conducted to investigate surface condition of pavement on steel plate deck of bridge. The results of the survey showed that main distress mode of the pavement are longitudinal cracks which occur at web of longitudinal rib as well as at the position between the webs. To make clear the causes of the crack, we performed strain analysis using overlaid FSM. The strain analysis indicated that, although large tensile strains appeared in the pavement at the web of rib, the strains between the webs were basically compressive. These results can not explain the cracks between the webs. Laboratory experiment modeling the pavement on plate deck was conducted and the results indicated the possibility of occurrence of the cracks by repetition of compressive strain.

押し剥離作用を考慮した合成梁の実用式について

Some composite beam problem requires the different boundary conditions in each beam. The degree of freedom in each node becomes three by permitting split-off action, and it becomes possible to treat the boundary conditions independently for the each beam terminal. The author develops new composite beam theory permitted this action and shows the effectivity of this theory by applying it to the problem of the composite floor slab smeared with the flexural cracks in the tension zone of the concrete portion. The solution of this illustrative problem also gives the explanation of the phenomenon of the observed poor composite action when we use some group of steel deck plates.

デッキプレートを用いた合成スラブ要素試験体による地震面内せん断力伝達機構に関する実験的研究

In cold-formed steel-deck concrete composite slab systems, it is important to make clear the seismic in-plane shear transfer mechanism of composite floor slabs. Herein, experimental studies are conducted by using thirty-five different full-scale test specimens with one unit element of steel-deck plate. During the test, alternately repeated in-plane lateral forces are applied to all the specimens on the laboratory test floor, and complete hysteresis loops for load and deformation relations are obtained. Test results indicate that all of the ultimate in-plane shear strengths and expected failure modes can be well expected by the existing theories.

Experimental study on ultimate strength of stiffened plates subjected to longitudinal tension and transverse compression

The ultimate strength of steel plates with longitudinal stiffeners of open or closed cross-section subjected to both longitudinal tension and transverse compression is experimentally investigated in this study. Four stiffened plate specimens on the scale of one-third, corresponding to that of the steel deck plate in an actual Nielsen Lohse bridge, were tested by using an experimental apparatus newly developed for this study. The test results verify a practical design method, which the authors developed for predicting the ultimate strength of stiffened plates subjected to biaxial in-plane forces.

Mission Bridge—Design and Construction of the Steel Box Girder

The main span of the four-lane highway Mission Bridge is 440 ft (134.1 m) long with 290 ft (88.4 m) flanking spans, and consists of a steel box girder with an orthotropic steel plate deck. A box girder was adopted due to the structural efficiency of the box section and advantages in using thin plate material. The design is based on CSA Standard S6-1966 and the AISC Design Manual for Orthotropic Steel Plate Deck Bridges as far as applicable and with some deviations. The design was reviewed subsequent to the failure of steel box girder bridges abroad. The strength of the bottom plate in compression and the transverse bolted joints in compression received special attention. The joints of the deck plate made in the field are welded.In the fabrication and erection of the bridge, advantage was taken of the marine location of the fabrication yard. Special erection equipment was developed for the job. A key element in the scheme was ease with which the erection crane scow could be positioned.The application of the hot asphaltic concrete paving caused considerable thermal expansion of the steel structure.The cost of the steel superstructure was about the same as was estimated for a concrete superstructure. However, site conditions were such that the weight of the concrete structure would have increased the foundation costs.

Application of Probabilistic Concepts for Determining Tolerance Limits of Initial Imperfection of Ship Plating

Generally, ship structure is constructed by welding and so it's member is always accompanied by welding residual stresses and initial imperfections.These residual stresses and initial imperfections reduce the ultimate strength, therefore it is very important to clarify the acceptable initial imperfection for safety design.This paper deals with studies on the tolerance limits of initial imperfections of the tanker's deck plates from the view point of strength.First, in the case of deck plate with initial imperfections and residual stresses under compressive load, stochastic natures of strength and load are studied by means of Extreme Theory.Then, tolerance limits are determined by applying reliability concepts to estimate the safety.To this end, two kinds of calculations are carried out. Firstly, the upper limit of initial imperfections is calculated so that the risk of failure of deck plate becomes equal to that of setting values. Secondly, it is selected the standard risk of failure to that of the mild steel deck plate. And the initial imperfections of the High Tensile Steel deck plate (in case of larger ship) is calculated in the same manner.It is found that the tolerance limits of initial imperfections in JSQS is reasonable around S/t= 40, but the larger the values of S/t, the smaller the safety of deck plate.These conclusions are obtained from comparison between ships smaller than 100, 000 DWT and larger one, therefore the conclusion is correct only in comparative sense.

Effective Width of Steel Deck-Plate in Bridges

The problem of the effective width, which is encountered in the design of steel plate deck bridges, is presented and examined theoretically. The differential equation of the correlated plane state of loading in the deck-plate is obtained taking in consideration the effect of the mutually perpendicular stiffeners. A solution for the equation is given and the effective width is calculated. Formulas and tables of the effective width are presented for the case of sine-wave loading on the main girders. The behavior of the effective width of the steel deck-plate is presented showing that in addition to the usual factors governing the effective width of isotropic flanges, the ratio of the cross-sectional area of the longitudinal stiffeners to the cross-sectional area of the skin-plate has a significant effect.

The Evolution of German Cable Stayed Bridges- An Overall Survey

The evolution of bridges with girders stayed by means of steel cables—referred to as "cable stayed bridges" or "cable cantilever bridges"—has taken place in a relatively short period, namely, about fifteen years. In the domain of highway bridges the structural system in question fills the gap that once existed between the "deck" type bridge (with the girders installed under the bridge deck) and the suspension bridge. It has, however, also been successfully applied to the construction of footbridges. As far back as 1950, more particularly for "deck" bridges, of medium span, the continuous solid-web superstructure with orthotropic steel deck plate functioning also as the top flange showed itself to be superior to other systems. For long spans, however, it necessitated considerable girder depths at the intermediate piers, e.g., as much as 33 ft for the worlds biggest bridge of this type, the bridge over the River Save at Belgrade. The bridge with plate girders of constant depth which has been built over the Sill near Innsbruck has a superstructure with a depth of about 25 ft for a span length of 650 ft, i.e., a depth/span ratio of 1/26. Be that as it may, all the cable-stayed bridges that have been built in Germany in recent years are based on the structural system comprising an orthotropic deck plate and continuous girders.

Wearing Surfaces for Orthotropic Decks

Chapter 8, "Wearing Surfaces", of the AISC Design Manual for Orthotropic Steel Plate Deck Bridges1 contains the most complete descriptions of current steel deck surfacing systems and specific information on surfacing materials to be found in English language references. This paper presents new information on steel deck surfacing systems in use in the United States, systems proposed for three large orthotropic steel plate deck bridges being constructed or to be constructed in North America, and suggestions on novel components for surfacing systems that possibly justify consideration and further research. Despite the number of unprotected steel plate deck bridges giving satisfactory service in this country, there is agreement that a steel plate bridge deck requires some type of surfacing. Most existing steel plate bridge decks employ "pattern" or "checkered" steel plates. Such plates have different regular patterns of metal projections on the plate surface. The principal objection to unprotected pattern plate for highway bridge decks has not been corrosion of the steel plate, but the low friction developed between the steel plate and rubber tires in most conditions of service. It is generally agreed that steel plate decks require surfacing to improve resistance to skidding. It then follows that the surfacing system must be impervious to moisture. Trapped moisture on a steel plate under a surfacing system, admitted through cracks or holes in the surfacing system, will create a corrosion condition considerably worse than if the surfacing system were not present. The importance of the steel plate deck in orthotropic plate construction, as a member to distribute loads to stringers and as the top flange of stringers and floor beams, requires that the steel deck not be subject to corrosion. Thus, the two foremost requirements for a steel deck surfacing system are that the system must not admit moisture to the steel plate and the surface of the system must provide good resistance to skidding.

The Poplar Street Bridge

The Poplar Street Bridge will cross the Mississippi, between East St. Louis and the central business district of St. Louis. In addition to carrying Interstate Routes 55 and 70, it will be the terminal for Interstate 44 from the west and Interstate 64 from the east. This will be the first long span orthotropic steel plate deck girder bridge to be constructed in the United States. A contract for the substructure has already been awarded, and the superstructure will be advertised for bids in mid-1964. At the Missouri end of the bridge is the Jefferson National Expansion Memorial, a National Park commemorating the Louisiana Purchase, which will be completed, with its 630-ft stainless steel arch, in 1965. The view of the river from the Memorial will be framed on the north by the fine old Eads Bridge, a deck type arch truss design built in 1874, and on the south by the new bridge. Immediately west of the Memorial and adjacent to the central business district is an 80-acre area being redeveloped around a 50,000-seat sports stadium, which will be completed about the same time as the bridge.