Slope Stability Calculator
Calculate factor of safety for slope stability using infinite slope method
About this calculator
This Slope Stability Calculator determines the factor of safety for slopes using the infinite slope method, a fundamental analysis technique in geotechnical engineering. The calculator evaluates whether a slope is stable by comparing the resisting forces (soil strength) to the driving forces (gravity and loads). Engineers, geologists, and construction professionals use this tool to assess landslide risk, design safe excavations, and ensure structural stability in hillside construction projects.
How to use
Enter the slope angle, soil unit weight, cohesion, and internal friction angle into the calculator. Input any additional loads or water table conditions if present. Click calculate to determine the factor of safety, where values above 1.0 indicate stable conditions and below 1.0 suggest potential slope failure.
Frequently asked questions
What factor of safety indicates a stable slope?
A factor of safety above 1.5 is typically considered safe for permanent slopes, while 1.3 may be acceptable for temporary excavations.
When is the infinite slope method most accurate?
The infinite slope method works best for long, uniform slopes with shallow failure surfaces and homogeneous soil conditions.
What soil parameters are needed for the calculation?
You need the soil's unit weight, cohesion, internal friction angle, and the slope angle to perform the stability analysis.