Design Examples of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 409

200 kN

200 kN

14.34 kN/m

A Case of loading 1

B

a

1.9 1.9

0.3 0.9

5m

Y B = 259.85 kN

Y A = 211.85 kN

200 kN 200 kN

14.34 kN/m

A

B Case of loading 2

1.9 0.6 1.9

0.6

5 m

Y B = 235.85 kN

Y A = 235.85

Figure 4.168 Cases of loading for the maximum bending moment acting on an
intermediate stringer.

is that the centerline of the stringer divides the spacing between the resultant
of the concentrated live loads and the closest load, with maximum bending
moment calculated at the closest load (point a in Figure 4.168 ), while the
second case of loading is that the centerline of the stringer is located in the
middle between the concentrated live loads, with maximum bending
moment located at midspan as shown in Figure 4.168 :

2 2

M L : L : ð case of loading 1 Þ ¼ 211 : 85 2 : 2 14 : 34 2 : = 2 ¼ 431 : 37 kNm

34 5 2 81 kNm

There is a single case of loading for live loads to produce a maximum
shear force at the supports of the stringer, which is shown in Figure 4.169 :
Q L : L : ¼ 387

M L : L : ð case of loading 2 Þ ¼ 200 1 : 9+14 : = 8 ¼ 424 :

:

85 kN
Bending Moment Due to Dead and Live Loads with Dynamic
Effect Added (M Ed )

M Ed ¼M D : L : g g + M L : L : g q ¼ 48 : 44 1 : 3 + 431 : 37 1 : 35

¼ 645 : 3kNm

It should be noted that, according to EC0 (BS EN 1990) [3.4], the per-
manent actions of steel self-weight and superimposed load should be