Approximate and refined analysis methods - Computational Analysis and Design of Bridge Structures - page 33

+

2

−

σ σ

σ σ

x y

= −

x y

+

2

σ τ

2 xy

2

2

2

τ

xy

tan 2 α =

−

σ σ

x y
When applying orthotropic plate model in deck analyses, deck is meshed
into regular plate elements. However, unlike an isotropic plate element, a
local coordinate system is required so as to define two directions that have
different bending stiffness.

2.4.3 Articulated plate method
When the transverse distribution of loads is only through shear forces
with no transverse prestressing forces, it is defined as articulated plate
or shear-key slab with idealized articulated plate model, as shown in
Figure 2.15. For this type of bridge that has small transverse bending stiff-
ness, the transverse flexural and torsional stiffnesses, D y and D yx , respec-
tively, in Equation 2.4 would approach zero; the longitudinal bending and
torsional stiffnesses, D x and D xy , respectively, are defined for different
types of bridges as (Jategaonkar et al. 1985; Bakht and Jaeger, 1985):

1. Slab bridge with solid block

E t
12

3

= (2.6)

D

x

G t

3

= if S > t

D

xy

3

(a)

(b)
Figure 2.15 Articulated plate model. (a) Plates connected by shear keys and (b) articu-
lated plate numerical model.