Design Examples of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 307

35 cm

y

1.4

x x

1

y

Figure 4.77 The cross section of the diagonal tension members D 5 and D 4 .

4.3.3.22 Design of the Diagonal Member D 5
We can also design the diagonal member D 5 , shown in Figure 4.77 , carrying
a maximum tensile design force of 1668.5 kN and a minimum compression
force of 526.5 kN. We can use the same cross section used for V 5 and
check the safety of the member against the tensile and compressive forces
as follows.

Design as a Tension Member
The bolts used in connecting the member with gusset plates are M27 high-
strength pretensioned bolts having a clearance of 3 mm (hole diameter
Ø ¼ 30 mm):

2cm 2

A¼ 35 1 :

4 2+37

:

2 1 ¼ 135

:

4cm 2

A net ¼ 135 : 2 4 3 : 0 1 : 4 ¼ 118 :

Af y
g M0 ¼

135 : 2 275 100

1

N pl , Rd ¼ ¼ 3,718,000N ¼ 3718 : 0kN > N Ed

: 0

¼ 1668 : 5kN

0 : 9 A net f u

g M2 ¼

0 : 9 11,840 430

1

N u , Rd ¼ ¼ 3,665,664N ¼ 3665 : 7kN

: 25

> N Ed ¼ 1668 : 5kN

Design as a Compression Member

l b x ¼ 9600mm
l b y ¼ 8640mm