Design Examples of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 268

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 69 : 75 1 : 3 + 549 : 9 1 : 35

¼ 833 : 04 kNm

It should be noted that, according to EC0 (BS EN 1990) [3.4], the
permanent actions of steel self-weight and superimposed load should be
multiplied by 1.2 at the ultimate limit state, while the permanent actions
of concrete weight should be multiplied by 1.35. Therefore, the total dead
load is calibrated and multiplied by 1.3. On the other hand, variable actions
comprising road traffic actions are multiplied by 1.35 at the ultimate limit
state. Once again, it should be noted that the load factors adopted in this
study are that of the ultimate limit state. This is attributed to the fact that
the finite element models presented in Chapters 6 and 7 can be used to ana-
lyze the bridges and provide more accurate predictions for the deflections
and other serviceability limit state cases of loading.

Shearing Force Due to Dead and Live Loads with Dynamic Effect Added (Q Ed )
Q Ed ¼Q D : L : g g + Q L : L : g q ¼ 46

: 5 1 : 3 + 403 : 02 1 : 35 ¼ 604 : 5kN

Design Bending Moment (M Ed ) and Shear Force (Q Ed )
M Ed ¼ 833 : 04 kNm

for classes 1 and 2

Q Ed ¼ 604 : 5kN

Design of Stringer Cross Section

W pl f y
g M0

M c , Rd ¼

W pl 275
1

04 10 6

833 : ¼

: 0

W PL ¼ 3,029,236mm 3 ¼ 3029 cm 3

ChooseUB610 229 113 (equivalent toAmericanW24 76), shown in
Figure 4.44 . W PL around x - x¼ 3281 cm 3 . To classify the cross section chosen,

s

235
f y

r

235
275

e ¼ ¼ ¼ 0 : 924