Heel slab design of a cantilever retaining wall: The maximum design bending moment in the heel is considered from which combination of actions?

Introduction / Context:
Heel slabs of cantilever retaining walls act as cantilevers from the stem. Accurate bending moment evaluation must include all vertical loads and upward soil pressure acting on the heel area.

Given Data / Assumptions:

• Heel slab with retained soil above it.
• Possible surcharge on backfill.
• Upward soil reaction distributed under the base.

Concept / Approach:

Bending results from downward loads (self-weight of concrete, weight of backfill, surcharge) balanced by upward soil reaction. Maximum heel moment occurs from their combined effect and must satisfy strength and serviceability.

Step-by-Step Solution:

Verification / Alternative check:

Check with stability analysis (sliding, overturning, bearing) to ensure reactions used are consistent with overall equilibrium.

Why Other Options Are Wrong:

Each single effect alone is incomplete; the heel must be designed for the combined action to be safe.

Common Pitfalls:

Omitting surcharge; ignoring heel self-weight; using uniform soil reaction regardless of resultant location.

Final Answer:

All of the above acting together