Deformation Modulus Estimation in Jointed Rock Masses

The deformation modulus of a rock mass quantifies its stiffness under load and is a fundamental parameter in the design and analysis of tunnels, caverns, dams and slopes. In jointed rock masses, the presence of fractures, joints and bedding planes reduces overall stiffness compared with intact rock and introduces scale-dependency and anisotropy. Traditional in situ methods such as plate load tests and borehole deformation measurements provide direct estimates but are often time-consuming, costly and sensitive to test configuration. To overcome these challenges, engineers and researchers have developed empirical correlations linking deformation modulus to rock mass classification indices, numerical modelling schemes that upscale intact rock properties through discrete fracture networks or synthetic rock masses, and data-driven approaches employing statistical and machine-learning techniques. The interplay between joint geometry, mechanical properties of intact rock, groundwater pressure and stress state dictates the effective deformation response. Accurate estimation of the deformation modulus in jointed rock masses thus underpins safe, economical and sustainable design in geo-engineering worldwide.

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Deformation Modulus Estimation in Jointed Rock Masses publication trend

The graph below shows the total number of articles in deformation modulus estimation in jointed rock masses across all publications each year (not limited to Nature Index journals).

Technical terms

Deformation modulus (E_d): A measure of the elastic stiffness of a rock mass under loading, reflecting its tendency to deform.

Jointed rock mass: A body of rock containing discontinuities such as fractures, joints and bedding planes that influence mechanical behaviour.

Rock Mass Rating (RMR): An empirical classification combining parameters such as uniaxial compressive strength, joint spacing and condition to assess rock quality.

Basic Quality (BQ) system: A block-quality classification method yielding an index used in empirical formulas to estimate deformation modulus.

Discrete Fracture Network (DFN): A numerical representation of individual fractures within a rock mass used to upscale properties from intact rock to fractured rock mass.

References

1. Estimation of Modulus of Deformation Using Rock Mass Rating—A Review and Validation Using 3D Numerical Modelling. Sustainability (2023).
2. An Appropriate Model for the Prediction of Rock Mass Deformation Modulus among Various Artificial Intelligence Models. Sustainability (2022).
3. An Investigation of the Mechanisms Involved in Plate Load Testing in Rock. Applied Sciences (2021).
4. New Method to Estimate Rock Mass Deformation Modulus Based on BQ System. Applied Sciences (2024).
5. Upscaling the Mechanical Properties of a Fractured Rock Mass Using the Lattice-Spring-Based Synthetic Rock Mass (LS-SRM) Modeling Approach—Comparison of Discontinuum, Continuum and Empirical Approaches. Geosciences (2022).