Melbourne sits on a mix of Quaternary basalts, Tertiary sediments, and recent alluvial deposits. The city's average elevation is only 31 m above sea level, but the Yarra River corridor and inner suburbs like Richmond and Abbotsford have deep soft clays and sands. For retaining wall design in Melbourne, the first step is classifying the soil type and its engineering behavior. We run Atterberg limits and sieve analysis to determine plasticity and particle size. These parameters feed directly into the corte directo test, which gives us drained and undrained shear strength values needed for active and passive earth pressure calculations. Without these numbers, a wall design is just a guess.
For retaining wall design in Melbourne, drained shear strength from triaxial tests is the most reliable input for long‑term earth pressure calculations.