Hoek Brown Criterion Calculator
Generalized Hoek-Brown peak strength sigma_1 = sigma_3 + sigma_ci*(m_b*sigma_3/sigma_ci + s)^a with m_b, s and a from GSI and the disturbance factor D (Hoek et al., 2002).
Description
Generalized Hoek-Brown peak strength sigma_1 = sigma_3 + sigma_ci*(m_b*sigma_3/sigma_ci + s)^a with m_b, s and a from GSI and the disturbance factor D (Hoek et al., 2002).
Hoek Brown Criterion Calculator: Generalized Hoek-Brown peak strength sigma_1 = sigma_3 + sigma_ci*(m_b*sigma_3/sigma_ci + s)^a with m_b, s and a from GSI and the disturbance factor D (Hoek et al., 2002).
When to use Hoek Brown Criterion
Use this geological calculation for a transparent first-pass interpretation of measured rock, soil, fluid, well, stratigraphic, isotopic, geophysical, or seismic data under an explicitly selected model.
- sigma_ci (MPa)
- Intact uniaxial compressive strength in megapascals.
- sigma_3 (MPa)
- Confining (minor principal) stress in megapascals.
- mi
- Intact rock constant mi for the lithology.
- GSI
- Geological Strength Index (0-100).
- D
- Blasting/excavation disturbance factor D (0-1).
How Hoek Brown Criterion works
Generalized Hoek-Brown peak strength sigma_1 = sigma_3 + sigma_ci*(m_b*sigma_3/sigma_ci + s)^a with m_b, s and a from GSI and the disturbance factor D (Hoek et al., 2002). The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.1
- sigma_1 (MPa)
- Major principal stress at failure in megapascals.
- m_b
- Hoek-Brown m_b parameter.
- s
- Hoek-Brown s parameter.
- a
- Hoek-Brown a exponent.
Limitations and assumptions
- Geotechnical correlations and idealized failure models depend on stratigraphy, sampling disturbance, drainage, stress history, groundwater, density, anisotropy, scale, construction sequence, and laboratory or field method. Site-specific design requires investigation and code factors.
- Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.
Alternative or Complementary approaches
Compare independent measurements and models, retain units and analytical metadata, propagate uncertainty, and validate interpretations against logs, cores, maps, laboratory data, or field observations.
References
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Geotechnical engineering — Wikipedia contributors
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