Numerical Investigation of Damage Risks of Roadway Surrounding Rocks under Oblique Incident Dynamic Loads

摘要

In order to quantitatively demonstrate the damage risks of roadway surrounding rocks and meanwhile comprehensively consider stress states of surrounding rocks, an index to evaluate damage hazards was established based on Mohr-Coulomb strength criterion. Taking the track roadway of Longwall Panel 402103 in Hujiahe Coal Mine as an example, damage risks and dynamic response characteristics of surrounding rocks under oblique incident dynamic loads were studied in accordance with the new evaluation criterion. The results show that all conventional analysis indexes only reflect the stress distribution characteristics of coal-rocks from a certain aspect in two-dimension space, while all stress components can be considered by the damage risk index, with the evaluation criterion quantified, which can comprehensively reveal the stress states and damage of coal-rock masses. Under dynamic loading, the overall damage risks and damage degrees of roadway surrounding rocks are attributed to the superposition results of dynamic and static loads. The dynamic loads not only aggravate the damage of shallow surrounding rocks but also increase the damage risks of deep parts. The engineering practice demonstrates that the analysis results coincide with in situ damage of roadway surrounding rocks.