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  Barton-Bandis Joint Parameters Database (CSV)
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DEFINITION
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The Barton-Bandis Joint Parameters Database (CSV) is a structured, open-format
dataset containing empirically derived rock joint properties used to characterize the
shear strength and deformability of natural discontinuities in rock masses. It
compiles measured or estimated values for key parameters—including Joint Roughness
Coefficient (JRC), Joint Wall Compressive Strength (JCS), and Basic Friction Angle
(φ_b)—as defined by the Barton-Bandis empirical model. This resource supports
quantitative rock mechanics analysis in mine ground control, slope stability, and
underground excavation design.

OVERVIEW
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The Barton-Bandis model is a cornerstone empirical framework in rock mechanics for
predicting the peak shear strength (τ_peak) and normal stiffness (k_n) of rock
joints under varying stress conditions. Developed by Nick Barton and colleagues in
the 1970s–1980s, it bridges field observations with numerical modeling by relating
measurable joint surface characteristics—such as roughness, wall strength, and
aperture—to mechanical behavior. The CSV database serves as a practical
implementation of this model, aggregating published and validated joint parameter
sets from diverse geological settings (e.g., granite, schist, limestone), often
accompanied by site context, measurement methods (e.g., JRC estimated via profile
tracing or visual comparison), and uncertainty notes. Each row typically represents a
discrete joint or joint set, enabling users to filter, calibrate, or benchmark
numerical models (e.g., in UDEC, Phase2, or RS2) or perform statistical analysis of
joint property distributions. Beyond deterministic analysis, the database facilitates
probabilistic ground support design and risk-informed stability assessments by
capturing variability in JRC, JCS, and φ_b across lithologies and tectonic
histories.

KEY COMPONENTS
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1. Joint Roughness Coefficient (JRC)
2. Joint Wall Compressive Strength (JCS)
3. Basic Friction Angle (φ_b)

APPLICATIONS
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  - Calibrating discrete element or continuum numerical models for mine pillar stability
  - Estimating in-situ joint shear strength for ground support selection (e.g., bolt length and spacing)
  - Supporting probabilistic rock mass classification (e.g., Q-system, RMi) and empirical design charts

KEY FORMULAS
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Barton-Bandis Peak Shear Strength: τ_peak = σ_n × tan[φ_b + JRC × log₁₀(JCS/σ_n)]
  -> Calculates the peak shear stress (τ_peak) of a rock joint under normal stress (σ_n), incorporating empirical roughness (JRC), wall strength (JCS), and basic friction angle (φ_b).
Barton-Bandis Normal Stiffness: k_n = (JCS / JRC²) × (σ_n / σ_ref)^0.5
  -> Estimates the normal stiffness (k_n, in MPa/m) of a closed rock joint, where σ_ref is a reference stress (typically 1 MPa); reflects scale- and stress-dependent joint closure behavior.

RELATED CONCEPTS
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  - Rock Mass Classification (Q-system)
  - Discontinuity Characterization
  - Empirical Rock Mechanics

REFERENCES
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Barton, N., Lien, R., & Lunde, J. (1974). Engineering classification of rock masses for the design of tunnel support (https://doi.org/10.1007/BF01239496)
Barton, N., & Bandis, S. (1990). Some fundamental concepts concerning discontinuity deformation. (https://www.researchgate.net/publication/237248513_Some_Fundamental_Concepts_Concerning_Discontinuity_Deformation)
International Society for Rock Mechanics (ISRM) Suggested Methods for Rock Characterization (https://www.isrm.net/suggested-methods/)

TAGS
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rock-mechanics, mine-ground-control, empirical-modeling, joint-parameters, csv-database