Economical depth of a plate girder is given by
where M is maximum moment in the plate girder, σtw is allowable bending stress and tw is thickness of web
The depth of plate girder is adjusted to get the minimum self-weight of the girder and that depth is called economical depth of plate girder,
σtw = Allowable bending stress in tension
Minimum spacing of vertical stiffeners is limited to
where d is the distance between flange angles.
Vertical stiffeners are provided at the spacing of 0.33 of to 1.5 d where d is the distance between the flanges ignoring fillets and if horizontal stiffeners are also provided d is the maximum clear depth of the web. Spacing can be reduced near the supports where the shear force is large compared to the centre of the girder.
Consider the following statements in respect of design of web and flange splices
1. Flange splice shall be designed for actual BM at the section
2. Flange splice shall be designed to resist the actual shear at the section
3. Web splice shall be designed to resist the actual shear at the section
4. Web splice shall be designed for actual BM
Which of these statements are correct
Consider the following statements:
Horizontal stiffener is provided when
1. The depth of web is small.
2. Tendency to web buckling is less.
3. Vertical stiffeners become too close.
4. Only thin plates are available for web.
Which of these statements are correct?
In steel bridges, for span less than 9 m and class AA loading for wheeled vehicles, the impact factor is taken as
Horizontal stiffeners are needed in plate girders if the thickness of web is
where d = distance between flanges;
L = span
Which one of the following is correct?
An intermediate vertical stiffener connected to the web is designed to withstand a shearing force of not less than
where t is web thickness in mm and h is the outstand of stiffener in mm.
As per clause 18.104.22.168 of IS: 800-1984, intermediate horizontal stiffeners not subjected to external loads shall be connected to web by rivets or welds, so as to withstand a shearing force, between each component of the stiffener and the web of not less than,
Which one of the following is the most efficient section for a simply supported gantry Girder.
In a plate girder, flange angle should be
Unequal flange angles with long horizontal leg; are provided to serve the following purposes:
1. To increase the moment of inertia of the section and
2. A large length is available for making the connection with the flange plate.
The forces acting on the web splice of the plate girder are