In hill road construction, what is the name of the wall built on the hill (cut) side to stabilize the excavated slope and prevent slips onto the roadway?

Introduction / Context:
Hill roads involve both cut slopes (hill side) and fill slopes (valley side). The slope on the hill side can ravel or slip if unsupported, endangering traffic. Specialized walls are used depending on location and purpose: breast walls on the hill side to hold the cut, retaining walls typically on the valley side to retain fill, and parapet walls as roadside safety/delineation barriers.

Given Data / Assumptions:

• Excavation has been made on the hill side (cut slope).
• Objective: stabilize the excavated face against local failures.
• Terminology follows Indian road engineering usage.

Concept / Approach:
A breast wall is constructed at or near the foot of the cut slope to support the uphill material and prevent small slips and rock falls. This is distinct from a retaining wall, which is commonly placed on the valley side to hold up embankment fill or to widen the roadway platform.

Step-by-Step Solution:
Identify the slope type: cut (hill) side.Map the correct structure: breast wall supports the cut slope.Exclude parapet (safety barrier) and valley-side retaining structures for this function.

Verification / Alternative check:
Standard hill road manuals and exam guides consistently define breast walls for hill-side stabilization, while parapet walls serve as edge protection and retaining walls hold fill on the valley side.

Why Other Options Are Wrong:

• Retaining wall: mainly for valley-side embankment retention in this context.
• Parapet wall: a safety/delineation barrier, not a slope-stabilizing wall.
• All of the above: incorrect because each wall has distinct functions.

Common Pitfalls:
Mixing terminology between valley and hill sides; assuming any wall near the road is a “retaining wall.”

Final Answer:
Breast wall