Empirical Evaluation of RMR, GSI, and Q for Underground Excavations

Abbas, Naeem; Li, Ke-Gang; Emad, Muhammad Zaka; Qin, Qingci; Li, Mingliang; Shah, Kausar Sultan; Yue, Rui; Qiu, Shuai

doi:10.1007/s40996-023-01275-8

Cited by 3 publications

(1 citation statement)

References 21 publications

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“…Smaller grain sizes typically enhance elasticity, while well-aligned grain boundaries can strengthen it further. Conversely, defects and phase transformations can introduce energy dissipation mechanisms, affecting the material's ability to store and release energy [42]. The interaction among these mineralogical constituents reveals the complex relationship between rock composition and mechanical behaviour.…”

Section: Rock Failure Modesmentioning

confidence: 99%

Influence of chemical composition and discontinuities on energy transformation and rock mass behaviour: Insights into geological dynamic

Abbas,

Li,

Fissha

et al. 2024

The Journal of Engineering

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In this study, efforts were made to incorporate the influence of discontinuities and failure modes of rock into the classification of rock masses. The past tectonic activities may create microfractures in the rock body therefore the failure moods have been determined carefully under uniaxial compression. The results of the discontinuity analysis, conducted through kinematic study, highlighted the significant impact of wedge failure on the failure of the rock mass. In correlating the geological strength index with rock mass rating, it was observed that joint volume played a negative role, whereas compressive strength played a positive role. These correlations are particularly applicable for a certain rock type, as the compressive strength is inherently dependent on the type of rock. The analysis of failure modes under uniaxial compression reveals that the dissipation energy coefficient initially undergoes rapid increase before reaching its minimum value at the failure stage. The microstructures of the rock effect significantly the elastic and dissipation energy characteristics. Specifically, the axial splitting failure mode emerges as predominant. Given the area's past tectonic activity, these results emphasize the impact of microfractures within the rock body. Relating the failure criteria with the chemical composition of rock types reveals that rocks abundant in SiO2, such as gabbronorite, tend to exhibit brittle failure. Additionally, a dominance of Al2O3 over Fe2O3 suggests a predisposition towards brittle failure, while an increased ratio of CaO to MgO implies increased susceptibility to compression.

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Section: Rock Failure Modesmentioning

confidence: 99%

Influence of chemical composition and discontinuities on energy transformation and rock mass behaviour: Insights into geological dynamic

Abbas,

Li,

Fissha

et al. 2024

The Journal of Engineering

Self Cite

View full text Add to dashboard Cite

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Comprehensive Analysis of Rock Brittleness: Exploring the Impact of Surrounding Excavations in Hard Rocks

Abbas,

2024

Geotech Geol Eng

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Enhancing tunnel stability in the Himalayas: Empirical design support through numerical modelling

Abbas,

Li,

Emad

et al. 2024

The Journal of Engineering

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This study focuses on assessing the effectiveness of an empirically recommended support design through numerical modelling. Numerical techniques are utilized to accurately evaluate tunnel stability under various geological conditions. Numerical analysis is conducted on two different rock types along the tunnel route, employing the recommended support design based on the existing rock mass rating (RMR) and Q‐system. Furthermore, support recommendations are made using the modified RMR and Q‐system, considering the impact of stress. The numerical analysis indicates that the support recommended by the existing RMR may not substantially impact the total displacement and vertical stresses around the tunnel crown in the “Fair” to “Poor” rock mass of the study area. However, extending the bolt length by modifying the RMR to incorporate stress effects results in a reduction of total displacement and vertical stresses, ultimately achieving a stable level. These results underline the importance of considering stress effects and utilizing modified support designs to enhance tunnel stability.

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Empirical Evaluation of RMR, GSI, and Q for Underground Excavations

Cited by 3 publications

References 21 publications

Influence of chemical composition and discontinuities on energy transformation and rock mass behaviour: Insights into geological dynamic

Influence of chemical composition and discontinuities on energy transformation and rock mass behaviour: Insights into geological dynamic

Comprehensive Analysis of Rock Brittleness: Exploring the Impact of Surrounding Excavations in Hard Rocks

Enhancing tunnel stability in the Himalayas: Empirical design support through numerical modelling

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