Application of a simplified method of calculating longitudinal moments to the Ontario highway bridge design code

Abstract

A manual method for calculating the design live load longitudinal moments in superstructures of most right bridges is presented. The bridge types that can be analysed by this method are: slab bridges. beam and slab bridges incorporating both steel and concrete beams, bridges incorpor-ating wooden beams, and slabs on hollow trapezoidal o r other such torsionally stiffbeams.The proposed method was developed by orthotropic plate theory, and was checked by the grillage analogy method. The basis of the method and details of development methodology are presented. The effect of the various parameters on the transverse distribution of longitudinal moments is discussed.The method is useful not only for the ease with which design longitudinal moments can be obtained, but also because it enables the designer to investigate the effects of making changes in the design on distribution characteristics.To demonstrate the simplicity of the solution a worked example is included. On u mis au point une methode d e calcul manuel des moments longitudinaux dus I la surcharge dans les superstructures de la plupart des ponts droits. Cette nlethode s'applique aux types d e ponts suivants: ponts-dalles, pont i poutres et dalle (poutres d'acier ou d e beton), pontscomportant des poutres de bois, et ponts 5 dalle sur caisson trapezo'idal ou d e rigidit6 torsionnelle analogue. La methode decoule de la theorie des dalles orthotropes et a ete ve~ifike au moyen d e I'analogie du grillage. Dans I'article, on retrouve le principe de la methode, les details d e son elabo~.ation et une discussion portant sur I'influence des divers parametres sur la repartition t~.ansversale des moments longitudinaux. La methode se revtle utile non seulenlent r' l cause d e la facilite qu'elle apporte au calcul des moments longitudinaux, mais aussi parce qu'elle permet i I'ingenieur d'etudier I'effet, s u r la repartition des efforts, d e changements apportes i certains parametres.Un exemple expose en detail illustre la simplicit6 d e la solution.Can. J. Civ. Eng.. 6 , 3 6 5 0 (1979) [Traduit par la revue]

Load Distribution In Adjacent Precast "Deck Free" Concrete Box-Girder Bridges

“…The maximum live load moment in each girder is obtained by multiplying the maximum moment due to the design live load by distribution factor D f . (Bakht, 1979) In 1979, Bakht et al used the concept of orthotropic plate to develop a simplified method for calculating the design live load longitudinal moments, see Figure 2.1. In their research, they conducted extensive parametric studies, which led them to find out that the distribution factor of bridges is related to a torsional parameter α and a flexural parameter θ, which are functions of geometry and material properties of the bridge.…”

Transverse Slab Reinforcement Design of Concrete Bridge Deck: A Review

“…Vehicular load model 1 Tandem system of Eurocode [104] would be adopted in the study. As the clear space between adjacent girder flanges is short (50,200 and 500mm), the vehicle wheel load would be directly supported by the prestressed concrete girders considering the fact that the vehicular wheel contact area is 460×460mm [105]. The surface of the T-beam would be rough and wet prior to the application of the top slab so as to obtain a better performance [106].…”

Analytical Solutions for Girder Distribution Factor in Steel‐Concrete Composite Girders with the Effect of Parapets

“…In this method, the GDF is linearly related to the spacing (S) of girders, while "D" is a constant related to the type and geometric properties of the bridge [2,3]. Before the 1990s, most investigations were focused on revising the parameter D by analytical methods or field tests [4][5][6]. After the 1990s, with the development of finite-element technology, Zokaie et al [7,8] investigated the influence parameters of the GDF by FE analysis and proposed the equations including span, spacing of girders, longitudinal stiffness of girders, and thickness of a concrete deck to calculate the GDF for moment of interior girders, while the GDF for moment of exterior girders was obtained based on the revision of equation for interior girders by the cantilever width of the deck.…”