Westergaard’s stress distribution: For which type of soil profile is Westergaard’s analysis most appropriately applied in foundation engineering?

Introduction / Context:
Stress distribution beneath loaded areas governs settlements and bearing capacity. Boussinesq’s theory assumes a homogeneous, isotropic, elastic half-space, whereas Westergaard developed an alternative model to handle particular soil structures.

Given Data / Assumptions:

• Soil may be non-homogeneous or layered.
• Elasticity-based analytical solutions are being considered.
• Interest is in vertical stress beneath surface loads.

Concept / Approach:
Westergaard’s analysis modifies the distribution of stresses to account for layered or stratified conditions, often assuming restricted lateral deformation (e.g., through reinforcement or lamination concepts). This contrasts with Boussinesq’s isotropic continuum. Consequently, Westergaard is preferred for stratified soils where layers significantly influence stress bulbs and settlements.

Step-by-Step Solution:

Verification / Alternative check:
Compare predictions from Boussinesq and Westergaard; layered cases often show different stress attenuation, matching field plate load or settlement observations better with Westergaard.

Why Other Options Are Wrong:

• Homogeneous sands or clays are classically treated with Boussinesq; Westergaard is tailored for stratified systems.

Common Pitfalls:
Applying homogeneous-half-space formulas to distinctly layered deposits without correction; this can misestimate settlements.

Final Answer:
Stratified soils (layered media)