Design Examples of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 433

wAf y
g M1

where N b , Rd ¼

1
F +

w¼ p but w 1 : 0

l 2 F 2

h i

+ l 2

51+ a l 0 F¼ 0 : : 2

¼ 0

365 2 F¼ 0 : 51+0 : 34 0 ð : 365 0 : 2 Þ +0 : : 595

1

w¼

595 +

p ¼ 0 : 939 but w 1 : 0

: :

595 2

0 :

365 2 0 0

:

939 232

:

4 275

0

Then, N b , Rd ¼ ¼ 5,455,590N

1 : 1

N b , Rd ¼ 5455 : > N Ed ¼ 4846 : ð : : Þ

6kN 8 kN Then O K

4.6.3.14 Design of the Lower Chord Member L 4 and L 5
Let us now design the tensile lower chord members L 4 and L 5 , shown in
Figure 4.194 , carrying a tensile design force of 11,039.3 kN. To assume a
reasonable cross section for the lower chord tension members, the following
parameters can be considered:

L
12 30 ¼

5000
12 30 ¼ 417 166mm,

h ¼ taken as 400 mm :

Once again, it should be noted that the gusset plates must be spaced at a
constant distance ( b ) of 400 mm. Let us start by assuming the flange and web
thickness of 26 mm (see Figure 4.194 ) . It should also be noted that the gross

b = 36 cm

2.6 y

x x

2.6

2.6

y

2.6

50 cm

Figure 4.194 The cross section of the lower chord tension members L 4 and L 5 .