Analyze the Underlying Cause: Disturbed Soil

What happens here

Following the visual of the failed wall, an expert explains the primary technical flaw. He states that the entire wall likely needs to be rebuilt because 'proper techniques clearly were not followed.' The key issue identified is the construction of the wall on 'disturbed soil,' specifically excavated soil that was then built up. This contrasts with the correct practice of building on 'undisturbed soil.' Building on disturbed soil means the foundation is unstable and prone to movement, rather than providing a solid base.

Goal: Understand the critical role of undisturbed soil in retaining wall stability.