Working through a calculation

The six-step wizard, live results and what governs.

This page walks through Bearing Capacity, which shows the pattern all the calculators follow.

The six steps

Step Covers
1 · Design basis Method, design approach, drainage condition
2 · Geometry Footing dimensions and depth
3 · Loads Applied loading
4 · Ground model Soil layers and properties
5 · Design settings Factors and design parameters
6 · Review Check inputs and results

Move between steps using the numbered tabs.

Design basis

Three choices that set everything downstream:

  • Calculation method — for example Terzaghi (default)
  • Design approach — for example Allowable stress
  • Drainage condition — for example Drained / effective stress

Drainage condition is the one to get right. Drained and undrained analyses of the same footing give different answers, and which applies depends on the soil and the loading rate.

Each field has a ? with guidance.

Reading the results

The results panel updates live:

  • Governing design pressure — the headline value in kPa
  • Utilisation — how much of the capacity the applied load uses
  • A line stating what governs, for example Terzaghi (1943) · bearing shear governs · Stiff clay

Two diagrams show the section — ground, footing, groundwater and layers — and the footing in plan with its effective contact area.

What governs

Always read the governing line. It tells you which failure mode and which layer control the result. A capacity governed by a soft layer well below the footing is a different design problem from one governed by shear at founding level, and the number alone does not tell you which you have.

Engine version

The header records the engine version, for example engine v1.0-beta. Note it for any calculation you issue.