ToolsGeotechnicalGround Stress & Earth Pressure

Overburden Pressure Calculator

Calculate total vertical stress, pore water pressure, and effective stress at depth for multi-layer soil profiles. Uses Terzaghi effective stress principle.

Last updated 1 February 2026

About this tool

Calculate total vertical stress (σv), pore water pressure (u), and effective vertical stress (σ'v) at any depth below ground level. Supports multiple soil layers with different unit weights.

Enter layer thicknesses, unit weights, and water table depth. The tool sums γ × h for each layer and applies the Terzaghi effective stress principle: σ'v = σv − u.

Essential for foundation design, consolidation analysis, and as an input to bearing capacity and lateral pressure calculations.

How to use this tool

1. Add soil layers — enter thickness (m) and bulk unit weight (kN/m³) for each layer from the surface down.

2. Enter water table depth — depth from ground surface. Leave blank if no water table above the calculation depth.

3. Read the stress results — total stress, pore pressure, and effective stress at the base of the deepest layer.

Technical information

σv = Σ(γi × hi) — total vertical stress

u = γw × (z − zw) — pore water pressure (γw = 9.81 kN/m³)

σ'v = σv − u — Terzaghi effective stress principle

Limitations

Assumes hydrostatic pore pressure below the water table. For artesian or perched water conditions, pore pressure should be measured directly.

Uses bulk unit weight throughout. For more precise calculations below the water table, use saturated unit weight for submerged layers.

Does not account for surcharge loads, capillary rise, or negative pore pressures above the water table.

Revision history

1 February 2026: Initial release

Disclaimer

This tool is provided for educational and general information purposes only. It is not a substitute for professional engineering advice, design or verification.

Diggy and its contributors are not licensed engineering consultants and no results generated by this tool should be used directly for construction, design or safety-critical decisions.

All values and outputs are based on published empirical correlations and should be independently checked and confirmed by a qualified geotechnical engineer before use.

By using this tool, you accept full responsibility for how you interpret and apply the information provided.

Spotted an error? Let us know.

Soil layers

Thickness (m)

Unit weight (kN/m³)

Water table depth (m)

Depth from ground surface to water table. Leave blank if no water table.

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