Geological Strength Index (GSI) Calculator

Estimate the Geological Strength Index (GSI) of a rock mass from rock structure and surface condition descriptors for use in Hoek-Brown strength criterion and rock mass property estimation.

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.
Advertisement

How It Works

Estimate the Geological Strength Index (GSI) of a rock mass from rock structure and surface condition descriptors for use in Hoek-Brown strength criterion and rock mass property estimation

Each component has a specific meaning:

  • Rock structure — The rock structure recorded for the patient or scenario being assessed.
  • Surface condition descriptors — The surface condition descriptors recorded for the patient or scenario being assessed.

Note: Interpret the geological strength index result against the clinical thresholds and context described above.

How to Use

Enter the rock structure, surface condition descriptors for the patient or scenario you are assessing. Estimate the Geological Strength Index (GSI) of a rock mass from rock structure and surface condition descriptors for use in Hoek-Brown strength criterion and rock mass property estimation. Use the geological strength index result to inform your clinical assessment.

Related Calculators

Hoek-Brown Criterion

Engineering

Rock Mass Rating RMR

Engineering

Q-System Rock Quality

Engineering

Frequently Asked Questions