Column bases in steel structures: which of the following statements are correct about their function and design intent?

Introduction / Context:
Column bases form the interface between steel columns and concrete foundations or pedestals. They ensure safe transfer of axial load, moments, and shear, while limiting bearing stresses in concrete.

Given Data / Assumptions:

• Steel column with base plate and anchors resting on concrete.
• Service loads within permissible bearing of concrete and plate bending capacity.

Concept / Approach:
The base plate distributes concentrated column reactions across a sufficient concrete area such that bearing pressure is acceptable. Simplified design commonly assumes an approximately uniform pressure distribution (with checks for moments and shear as required) and designs plate thickness and anchors accordingly.

Step-by-Step Solution:

Verification / Alternative check:
Check concrete bearing stress = Load / Bearing area and confirm within limits; cross-check with more refined pressure distribution if significant moments exist.

Why Other Options Are Wrong:
Options (a)–(d) are all correct, so choosing a subset would be incomplete.

Common Pitfalls:
Ignoring eccentricity and resultant moments; undersized plate thickness leading to excessive plate bending; neglecting grout and levelness.

Final Answer:
All the above