Rigid pavement analysis: For the design of cement concrete pavement under corner loading, which formula does the Indian practice (IRC) recommend?

Introduction / Context:
Cement concrete (rigid) pavements are analyzed for critical load positions: interior, edge, and corner. Corner loading is particularly severe because slab support is limited, leading to higher tensile stresses at the top or bottom fibers depending on conditions.

Given Data / Assumptions:

• Rigid slab resting on subgrade idealized as a dense liquid or Winkler foundation.
• Corner load case considered critical for design.
• Standard Indian practice references classical analytical solutions.

Concept / Approach:

Westergaard’s theory provides closed-form stress solutions for different load positions accounting for slab dimensions, load radius of contact, modulus of subgrade reaction, and slab stiffness. For corner loads, the stress expression allows designers to check slab thickness and joint layout to prevent cracking.

Step-by-Step Solution:

Verification / Alternative check:

Modern mechanistic–empirical methods still rely on Westergaard principles for baseline checks, corroborating its continued relevance in design manuals.

Why Other Options Are Wrong:

• Kelly, Goldbeck, Spanlar, Picker: not the standard corner-load reference in IRC-based rigid pavement design.

Common Pitfalls:

• Using interior-load formulas for corner cases, underestimating tensile stress.

Final Answer:

Westergaard's formula.