Year: 2025
Type: article
Abstract: To address the coal and gas outburst risks in the soft-hard composite coal seam, a three-dimensional (3D) model of the soft-hard composite coal seam of Hudi Coal Mine in China was constructed, incorporating coal creep effects.The influence of punching parameters (diameter, spacing, direction, and creep duration) on stress-damage evolution, pressure-relief range, and gas seepage behaviour in the coal seam was analysed.Results revealed that under the viscoelastoplastic model, creep deformation in soft coal zones expanded the pressure-relief range by approximately 30 % compared to elastoplastic models, with more stable gas seepage pathways.Directional punching along the maximum principal stress direction induced oriented fracture propagation, improving pressure-relief efficiency by over 25 %.Key parameter findings include: a critical punching diameter of 1.5 m (beyond which collapse risks increase), optimal spacing of 6.0 m, and stabilized pressure-relief effects after 40 d of creep.This study provides a theoretical basis for enhancing hydraulic punching efficiency and gas drainage performance in soft-hard composite coal seams.
Authors: Y. B. Chen, S. Zhang, S. R. Wang, Y. X. Cao, M. Lutynski
Institution: Henan Polytechnic University
Language: English
Subfield: Safety, Risk, Reliability and Quality
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
Awards: G1414101660, G163875880
OpenAlex ID: W4413958674