The stone layer is required to be what shape installed perpendicular to the slope?

The stone layer is required to be what shape installed perpendicular to the slope?

• A. Rectangular
• B. Circular
• C. Square
• D. Irregular

Answer: (A)

Stability of a stone layer on a slope depends on preventing movement from gravity and runoff. Placing the stone layer across the slope (perpendicular to it) creates a cross-slope barrier that slows surface water, distributes forces more evenly, and helps keep the layer in place rather than letting it slide downslope. The shape matters because rectangular stones provide flat, long faces that can be laid edge-to-edge to form a continuous, stable surface with minimal gaps. This makes the layer less prone to shifting and easier to pack tightly against adjacent stones. Circular stones tend to roll and settle unevenly on a slope, which compromises continuity. Irregular shapes leave gaps and don’t pack reliably, reducing stability. Rectangular stones therefore offer the most reliable, uniform cross-slope layer.

Stability of a stone layer on a slope depends on preventing movement from gravity and runoff. Placing the stone layer across the slope (perpendicular to it) creates a cross-slope barrier that slows surface water, distributes forces more evenly, and helps keep the layer in place rather than letting it slide downslope. The shape matters because rectangular stones provide flat, long faces that can be laid edge-to-edge to form a continuous, stable surface with minimal gaps. This makes the layer less prone to shifting and easier to pack tightly against adjacent stones. Circular stones tend to roll and settle unevenly on a slope, which compromises continuity. Irregular shapes leave gaps and don’t pack reliably, reducing stability. Rectangular stones therefore offer the most reliable, uniform cross-slope layer.