Approximate and refined analysis methods - Computational Analysis and Design of Bridge Structures - page 17

Approximate and refined
analysis methods
2.1 INTRODUCTION
This chapter will serve as the introduction of succeeding chapters, especially
chapters in Part II — Bridge Behavior and Modeling. Brief discussion of
various bridge structural forms will be made first in this chapter, whereas
more details on each bridge type will be covered in their individual chapters
(Chapters 4 through 12). Approximate and refined analysis methods with
their advantages and disadvantages will then be briefly mentioned (Coletti
and Pucket 2012). Although all methods can be categorized as finite element
method (FEM), levels of approximation and accuracy are different among
various modeling methods. With today's advancing of computer analysis
tools, there is a certain advantage to a adopting two-dimensional (2D) model
in grillage or three-dimensional (3D) model, as called refined analysis mod-
els, over one-dimensional (1D) model, as termed approximate analysis model.
Subsequently, the principle of FEM of all types will be presented in Chapter 3.
2.2 VARIOUS BRIDGE STRUCTURAL FORMS
Bridge systems consist of super- and substructures. The structural model
may couple them together where the effect of substructure is essential to
the whole analysis, such as earthquake analysis, or have them decoupled at
the bearing where the substructure does not affect much on the superstruc-
ture behavior, except drastic movement, such as support settlement. This
bridge system can be analyzed as a 1D model, which AASHTO termed
approximate analysis model, 2D model in grillage, or 3D model, where
the latter two can be categorized as refined analysis models. This chapter
identifies bridge deck structural forms and basic characteristics of these
different types of bridges. More details on all types of bridges and their
analyses will be covered in the Chapters 4 through 12 and 14 through 17.
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