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3.0
9.0
8.0
2.5
7.0
6.0
D
2.0
5.0
4.0
R
(a)
3.0
1.5
2.0
1.0
1.0
0.5
1.0
1.5
D
/
R
2.0
2.5
(b)
Figure 17.15
Embedment factor (
β
). (a) Embedment dimensions. (b) Embedment factor.
17.3.3 nonlinear analysis
Nonlinear dynamic analysis typically involves the development of a complex
bridge mathematical model with highly localized (rather than global) non-
linear behavior. The interior expansion joints and the abutment joints are
modeled using zero-length elastoplastic gap-hook elements. Based on the
report by Aviram et al. (2008), Table 17.5 summarizes the recommended
linear and inelastic modeling of the primary components of an ordinary
standard bridge structure. The behavior of the plastic hinge can be cat-
egorized by a yield surface and a moment-rotation relation. The yield sur-
face defined the interaction between axial force, weak and strong bending
moments, and even torque. However, it should be aware that nonlinear
dynamic analysis is problematic for routine application with reasonable
nonlinear components, sensibility to the details of the model, and inten-
sive output interpretation (Fu and Ahmed 2012). However, for bridges of
importance (those categorized as other than ordinary), an inelastic static
analysis should be performed.
17.3.3.1
Nonlinear static—Standard pushover analysis
AASHTO guide specifications (2012) also recommend pseudostatic ''push-
over analysis'' be used for the displacement-based performance design
method. This procedure examined the nonlinear response of a structure as
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