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Failure mechanism of gob-side entry in weakly cemented soft rock and bolt-grouting collaborative control method: a
Kai Zhou1,2,3, Chengfu Ma4,5, Fenghai Yu2
1Ordos Haohua Hongqingliang Mining Co., Ltd, Ordos, 014399, China.
Scientific Reports
|July 9, 2026
Summary
Weakly cemented soft rocks in Chinese coal mines cause roadway instability. A new bolt-grouting method was developed, significantly reducing deformation and improving roadway stability.
Area of Science:
- Geotechnical Engineering
- Mining Engineering
- Materials Science
Background:
- Weakly cemented soft rocks in western China exhibit low strength and disintegrate with water exposure.
- Traditional bolt support is insufficient for long-term roadway stability, leading to severe deformation and failure.
- Gob-side roadways are particularly susceptible to large-scale roof fracturing and failure.
Purpose of the Study:
- To investigate the failure mechanism of roadways supported by bolts in weakly cemented soft rock environments.
- To analyze the influence of roadway geometry and stress conditions on surrounding rock deformation.
- To develop and validate an effective collaborative support method for enhancing roadway stability.
Main Methods:
- Experimental characterization of weakly cemented soft rock properties.
- Theoretical calculation of tangential stress around rectangular roadways.
- Numerical simulations to assess the impact of roadway width and lateral pressure coefficient.
- Investigation of grout consolidation body properties and grouting effects.
- Field measurements and validation of the proposed support method.
Main Results:
- The support failure mechanism was identified as fracturing within the anchored section of roof bolts.
- Roadway width and lateral pressure coefficient were confirmed as key factors influencing surrounding rock deformation.
- Numerical simulations showed expansion of the plastic zone with increased roadway width and lateral pressure.
- A bolt-grouting collaborative support method was proposed and tested.
- Field tests demonstrated a reduction in roof-to-floor convergence by over 60%.
Conclusions:
- The developed bolt-grouting collaborative support method effectively enhances roadway stability in weakly cemented soft rock.
- Understanding the failure mechanisms and influencing factors is crucial for designing robust support systems.
- This integrated approach offers a promising solution for mitigating roadway deformation and failure in challenging mining conditions.
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