What is the general formula for factor of safety against sliding?

FS = Resisting Forces / Driving Forces = (c × A + N × tanφ + Passive) / (H - Tensile anchor), where c is cohesion (kPa), A is base area (m²), N is effective normal force (kN), φ is friction angle (degrees), and H is horizontal driving force (kN). For gravity dams: FS ≥ 1.5 (unusual loads), FS ≥ 2.0 (usual loads) per USACE EM 1110-2-2200.

How does drainage condition affect FS against sliding?

Pore water pressure reduces effective normal force and hence frictional resistance. In undrained conditions (short-term), use total stress (Su); in drained conditions (long-term), use effective stress (c', φ'). For foundation design, both conditions should be checked and the lower FS governs. Uplift pressure beneath structures (particularly gravity dams and spillways) must be included per USACE EM 1110-2-2200.

Factor of Safety Against Sliding

Calculate factor of safety against sliding for foundations, gravity dams, retaining walls, and soil/rock blocks on inclined surfaces using Mohr-Coulomb shear strength.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How It Works

Calculate factor of safety against sliding for foundations, gravity dams, retaining walls, and soil/rock blocks on inclined surfaces using Mohr-Coulomb shear strength

Each component has a specific meaning:

Mohr-Coulomb shear strength — The mohr-coulomb shear strength recorded for the patient or scenario being assessed.

Note: Interpret the factor of safety sliding result against the clinical thresholds and context described above.

How to Use

Enter the Mohr-Coulomb shear strength for the patient or scenario you are assessing. Calculate factor of safety against sliding for foundations, gravity dams, retaining walls, and soil/rock blocks on inclined surfaces using Mohr-Coulomb shear strength. Use the factor of safety sliding result to inform your clinical assessment.

Related Calculators

Retaining Wall Sliding

Engineering

Bishop Slope Stability

Engineering

Mine Slope Stability

Engineering

Factor of Safety Against Sliding

How It Works

How to Use

Related Calculators

Frequently Asked Questions

What is the general formula for factor of safety against sliding?

How does drainage condition affect FS against sliding?