What is Eurocode 7 (EC7)?

Eurocode 7 (EN 1997) is the European standard for geotechnical design. It defines principles, application rules and partial factor design methods for foundations, retaining structures, slopes and ground improvement. It is used together with Eurocode 0 and Eurocode 1 for load and combination rules.

Which design approaches does this Eurocode 7 calculator support?

This calculator supports the three design approaches defined in Eurocode 7: DA1, DA2 and DA3. For each approach it applies typical partial factors on actions, material parameters and resistance. You can override the default values to match your National Annex.

Can I use this tool for final design?

No. The calculator is intended as an educational and preliminary design aid. It simplifies several aspects of Eurocode 7 and does not replace detailed calculations, numerical analysis or professional judgement. Always have designs checked and approved by a qualified geotechnical engineer.

Does the calculator include National Annex settings?

The tool provides commonly used default partial factors, but National Annexes may specify different values and preferred design approaches. You should always confirm the correct factors for your country or project and adjust the inputs accordingly.

Engineering Eurocode 7 – Geotechnical Design Toolkit (EC7)

Interactive helper for Eurocode 7 geotechnical design: choose design approach, apply partial factors, and check bearing and sliding resistance with transparent step‑by‑step calculations.

This tool is for educational and preliminary design use only. Always verify results against the full standard, National Annex and professional judgement.

1. Design approach & limit state

Design approach (EN 1997-1)

Defaults are indicative only. Adjust to your National Annex.

Limit state

2. Bearing resistance check (shallow foundation)

Soil parameters (characteristic)

Unit weight γ_k (kN/m³)

Cohesion c'_k (kPa)

Friction angle φ'_k (°)

Geometry & actions

Footing width B (m)

Foundation depth D_f (m)

Vertical action V_k (kN)

γ_G (permanent)

γ_Q (variable)

γ_R (bearing resistance)

Eurocode 7 partial factors reference

This table summarises typical partial factors used in Eurocode 7 design approaches. Always check your National Annex for project‑specific values.

Quantity	DA1 (A1+M1+R1 / A2+M2+R1)	DA2 (A1+M1+R2)	DA3 (A2+M2+R3)
Permanent actions G	γ_G ≈ 1.35	γ_G ≈ 1.35	γ_G ≈ 1.0–1.35
Variable actions Q	γ_Q ≈ 1.5	γ_Q ≈ 1.5	γ_Q ≈ 1.3–1.5
Shear strength tan φ'	γ_M ≈ 1.0–1.25	γ_M ≈ 1.25	γ_M ≈ 1.25
Cohesion c'	γ_M ≈ 1.25	γ_M ≈ 1.4	γ_M ≈ 1.4
Resistance R	γ_R ≈ 1.0–1.4	γ_R ≈ 1.4	γ_R ≈ 1.2–1.4

Values above are indicative and compiled from common practice and literature. They are not a substitute for the official standard.

How this Eurocode 7 calculator works

This tool implements a simplified Eurocode 7 workflow for shallow foundations. It helps you understand how partial factors, design approaches and soil parameters interact, while keeping the calculations transparent.

1. Bearing capacity model

For the bearing check, the tool uses a Terzaghi-style expression for ultimate bearing resistance per metre length of footing:

Characteristic ultimate resistance

\( q_{ult,k} = c'_k N_c + \gamma_k D_f N_q + 0.5 \gamma_k B N_\gamma \)

where \(N_c, N_q, N_\gamma\) are bearing capacity factors derived from φ′_k.

Design resistance (simplified):

\( R_d = \dfrac{q_{ult,k} \cdot B}{\gamma_R} \)

Vertical actions are factored using γ_G and γ_Q to obtain V_d. The utilisation ratio is:

\( \eta_{bearing} = \dfrac{V_d}{R_d} \)

2. Sliding resistance model

For sliding, the base resistance is computed from design vertical force and interface parameters:

Design sliding resistance

\( R_{d,sliding} = \dfrac{V_d \cdot \mu_d + A \cdot c_{a,d}}{\gamma_R} \)

with \(V_d\) and \(H_d\) obtained from characteristic actions and partial factors γ_V, γ_H.

3. Design approaches (DA1, DA2, DA3)

Eurocode 7 defines three design approaches that distribute partial factors between actions, material parameters and resistance. National Annexes choose which approach to use for each type of structure.

DA1: two combinations (A1+M1+R1 and A2+M2+R1).
DA2: factors mainly on resistance (R2).
DA3: higher factors on actions (A2) and materials (M2), lower on resistance (R3).

This calculator lets you select the approach and adjust the partial factors so you can see the impact on design values.

Limitations and good practice

The bearing model ignores load inclination, eccentricity, base roughness and shape factors.
Groundwater, layered soils, seismic actions and consolidation effects are not explicitly modelled.
Serviceability checks (settlement, rotation) are not included and must be assessed separately.

Use this tool for concept design, teaching and quick sensitivity studies. For final design, follow the full text of EN 1997, the relevant National Annex and any project specifications.

Frequently asked questions

Is this calculator compliant with the second generation of Eurocode 7?

The tool is based on the first generation of Eurocode 7 (EN 1997‑1). Many principles carry over to the second generation, but numerical values and procedures may change. Always verify against the latest published standard.

Can I export the results?

You can copy the reported inputs and outputs directly into your design notes. For formal reports, include full hand calculations or software output from a validated design package.