The intermediate transverse stiffener is needed in plate girder when (d/tw) of web is
where d = depth of web;
tw = thickness of web plate
IS : 800-1984 recommends the provision of web stiffeners as follows:
No stiffener is required
Vertical stiffeners are provided.
Vertical stiffeners and one horizontal stiffener at a distance from the compression flange equal to two-fifths of the distance from the compression flange to the neutral axis are provided.
The requirement is the same as in (iii) plus a horizontal stiffener at the neutral axis, where d2 = 2 x clear distance from compression flange angles or plate or tongue plate to the neutral axis.
Economical depth of a plate girder corresponds to
Shear buckling of web in a plate girder is prevented by using
Consider the following statements:
Bearing stiffeners are provided in a plate girder
1. to avoid local bending failure of flange
2. to prevent buckling of web
3. to strengthen the web
4. under the uniformly distributed loads
Which of these statements are correct?
Bearing stiffeners are p ro vid e d under the concentrated loads and end reactions. It serves two purposes.
(i) It prevents the web from crushing and sideways (lateral) buckling under the load.
(ii) It relieves the rivets connecting the flange angles and web from vertical force.
For a welded plate girder with vertical stiffeners, what is the maximum depth of web provisionable in design when the thickness of the web plate is 5 mm?
Vertical stiffness are required in a welded plate girders when,
∴ dmin > 85 x 5 = 425 mm
dmax ≤ 200 x 5 = 1000 mm
List-I contains some elements in design of a simply supported plate girder and List-II gives some qualitative locations on the girder. Match the items of two lists as per good design practice and relevant coda! provisions.
A. Flange splice
B. Web splice
C. Bearing stiffeners
D. Horizontal stiffener
1. At supports (minimum)
2. Away from centre of span
3. Away from support
4. In the middle of span
5. Longitudinally somewhere in the compression flange
A B C D
(a) 2 3 1 5
(b) 4 2 1 3
(c) 3 4 2 1
(d) 1 5 2 3
Horizontal stiffener in a plate girder is provided- to safeguard against
Minimum thickness of web in a plate girder, when the plate is accessible and also exposed to weather, is
When vertical intermediate stiffeners are subjected to bending moments due to eccentricity of vertical loads, their moment of inertia (cm4) is increased by
M = the applied bending moment kN-m
D = overall depth of girder in mm
E = Young’s modulus in MPa
t = thickness of web, mm
The web crippling due to excessive bearing stress can be avoided by