In stone masonry using stratified rocks, how should stones be oriented relative to their bedding planes under service load? (Select the best practice for load direction versus bedding.)

Introduction:
Stratified stones (e.g., sandstones, limestones) have planes of weakness along bedding. Masonry durability and capacity depend on placing these stones so that loads act favorably relative to bedding.

Given Data / Assumptions:

• Service load is primarily compressive.
• Stratified rocks may split or shear along bedding if stressed unfavorably.
• Goal is maximum stability and weathering resistance.

Concept / Approach:
Best practice is to set stones so the load acts normal (at right angles) to bedding. This minimizes the tendency to delaminate and improves compressive performance, akin to loading timber perpendicular to grain for strength and stability.

Step-by-Step Solution:

Verification / Alternative check:
Construction handbooks consistently specify “load normal to bedding” for stratified blocks in courses, particularly for weathered stones.

Why Other Options Are Wrong:

• 45° or 60°: induce shear along bedding and stress concentrations.
• Parallel: highest risk of lamination separation and bending along weak planes.
• None of these: incorrect because a clear best practice exists.

Common Pitfalls:
Orienting stones for visual grain instead of structural performance; placing face-bedded stones in steps or copings where weathering rapidly exploits laminations.

Final Answer:
At right angles to the bedding plane (load normal to bedding)