Question

If 't' is the thickness of web of plate girder which is stiffened vertical then, the smallest clear dimension of a panel should not exceed:-
1. 85 t
2. 180 t
3. 250 t
4. 200 t

Answer 1

Correct Answer - Option 2 : 180 t

Explanation: 

As per IS 800:2007 In the case of plate girder with vertical stiffeners and horizontal stiffeners the lesser and greater unsupported clear dimension of web panel should not exceed 180 t and 270 t respectively. 

• Theoretically, intermediate transverse stiffener are not required when the calculated shear stress in the web is less than the critical shear stress of the web of the plate girder since the web will not buckle and failure of web will occur due to shear yielding of the web. Here tension field will not develop and stiffener are not required and the web completely be shear resistant. 
• minimum spacing of vertical stiffener = 0.33d
• maximum spacing of vertical stiffener = 1.5d
• Lesser clear panel dimension is less than 180t_w
• Greater clear panel dimension is less than 270t_w