According to IS 800-1984, the minimum thickness of the vertically
A. <span class="math-tex">\(\frac{d}{{85}}\)</span>
B. <span class="math-tex">\(\frac{d}{{200}}\)</span>
C. <span class="math-tex">\(\frac{d}{{225}}\)</span>
D. <span class="math-tex">\(\frac{d}{{250}}\)</span>
Please scroll down to see the correct answer and solution guide.
Right Answer is: B
SOLUTION
Transverse Stiffeners are provided to increase buckling resistance of the web due to shear, It is provided vertically along the span.
Horizontal Stiffener / Longitudinal Stiffener is designed to prevent web buckling due to bending compression.
End Bearing Stiffeners are provided at the supports & Load Bearing Stiffeners are provided at the points of concentrated loads.
Important Point:
if \(\frac{d}{{{t_W}}}\)< 67ϵ ⇒ unstiffened girder can be designed i.e. No girder required.
If 85 ϵ < \(\frac{d}{{{t_W}}}\)< 200 ϵ ⇒ Vertical stiffener (C1 and C2 ) may be provided.
i.e. d/200 < tw
tw > d/200
∴ Thickness of web should not be less than d/200
If 200 ϵ < \(\frac{d}{{{t_W}}}\) < 250 ϵ ⇒ Vertical stiffener along with longitudinal stiffener at 0.2 d may be provided.
If 250 ϵ < \(\frac{d}{{{t_W}}}\) < 345 ϵ ⇒ Vertical stiffeners along with two longitudinal stiffeners at 0.2 d and 0.5 d respectively may be provided.
Note: If not given, ϵ should be taken equal to 1.
