Approximate and refined analysis methods - Computational Analysis and Design of Bridge Structures - page 43

6.1 MN m −2 0

−1.9

0

0.7

+1.2 M T

Figure 2.25 Bridge thermal loading due to differential temperature.

1.5 m 1.5 m

100 kN/m

F = 938 kN

300 mm

80 mm
300 mm

3 12′′

2

1

10 kN/m 10 kN/m

25 kN/m 25 kN/m

80 mm 80 mm

A B C

(a) (b)

7.5 m 7.5 m 7.5 m 7.5 m

Figure 2.26 (a, b) Bridge prestressing loading as equivalent applying forces.

where:
E = Young's modulus of soil
G = Shear modulus of soil = E /[2(1 + ν)]
ν = Poisson's ratio of soil
A = Foundation area
Z = Foundation section modulus (Richart et al. 1970)

Structures with soil spring will be applied to earthquake analysis covered
in Chapter 17.

2.5.2 Slab bridge
In the AASHTO LRFD Specifications (2013), a beam model with equiva-
lent strip width can be built for the slab bridge. With one-lane loaded, the
equivalent width of longitudinal strips is (AASHTO Equations 4.6.2.3-1
and -2)

E = 250 . + 0 42

1

(2.12)

LW

1

and with multilane loaded,

W
N

E = 2100 . + 0 12 ≤ (2.13)

LW 1 1