Question

The minimum thickness of the web in a plate girder, when the plate is accessible and also exposed to weather is

• A. $ 5 \, \text{mm} $
• B. $ 6 \, \text{mm} $
• C. $ 8 \, \text{mm} $
• D. $ 10 \, \text{mm} $

Hint:

For steel structures exposed to environmental conditions, always check the relevant clauses in IS 800:2007 for minimum thickness requirements to ensure safety, durability, and economy.

Answer 1

The Correct Option is B

Step 1: Understand the requirement for web thickness in plate girders.
The web of a plate girder must resist shear forces and remain stable under load. When it is both accessible and exposed to weather, corrosion resistance becomes an important factor. According to IS 800:2007, the Indian Standard Code for Steel Structures, the minimum thickness of the web in such conditions is specified as: $$ \boxed{6 \, \text{mm}} $$
Step 2: Evaluate other options.
$ 5 \, \text{mm} $: Too thin; may not meet strength or durability requirements.
$ 8 \, \text{mm} $: Acceptable but not the minimum standard.
$ 10 \, \text{mm} $: Exceeds the required thickness unnecessarily, increasing cost and weight.
Step 3: Select the correct option.
Based on IS 800:2007, the correct minimum thickness is $ 6 \, \text{mm} $.