Isolated column footings — choose the correct combined statement Which of the following statements about isolated footings for columns are correct in standard building practice?

Introduction / Context:
Isolated footings are the most common shallow foundation for individual columns in buildings. Their geometry and reinforcement are tailored to spread load, control shear and bending, and achieve economical construction while meeting serviceability requirements.

Given Data / Assumptions:

• Columns carry axial load (and possibly some moment).
• Footing placed on compacted soil with adequate bearing capacity.
• Standard detailing used for reinforcement and offsets.

Concept / Approach:
An isolated footing transfers column loads to soil; steps or projections help achieve the required bearing area and reduce concrete volume compared to a uniform thick slab. Heavily loaded bases require two-way reinforcement to resist bending in both orthogonal directions. A practical concrete projection (offset) of roughly 150 mm on each side beyond the footing edge is a common detailing guideline to ensure cover, workable edge distances, and formwork stability (exact values vary by code and design).

Step-by-Step Solution:

Verification / Alternative check:
Typical detailing handbooks show two-way reinforced pads with plan projections and, where required, shear checks and punching reinforcement near columns.

Why Other Options Are Wrong:

• Choosing any single statement omits other equally correct aspects.

Common Pitfalls:
Ignoring punching shear at column faces; neglecting soil variability; omitting adequate cover at footing edges.

Final Answer:
All the above