Coal Engineering ›› 2025, Vol. 57 ›› Issue (7): 53-59.doi: 10. 11799/ ce202507008

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Research and application of full section anchor-grouting support in high stress soft rock roadway

  

  • Received:2024-10-17 Revised:2024-12-12 Online:2025-07-11 Published:2025-08-14
  • Contact: 程 利兴 E-mail:chenglixinghpu@163.com

Abstract:

In order to solve the technical difficulties in controlling the deformation of surrounding rock in deep well high stress soft rock tunnels, taking the No. 2 main drainage bin of Yadian Coal Mine as the research background, the distribution of rock stress, mineral composition and content of surrounding rock were tested, the deformation and failure characteristics of surrounding rock were analyzed, and the influencing factors and mechanisms of deformation in high stress soft rock tunnels were studied. The results show that the deformation of the surrounding rock in the roadway is mainly manifested by strong bottom bulging and severe internal squeezing of the roadway walls. The content of expansive clay minerals in the surrounding rock is as high as 95%. The strength attenuation and structural degradation of the surrounding rock when it encounters water are prominent, which constitute the main internal factors affecting the deformation of the surrounding rock. Low support strength and high geostress constitute the main external factors affecting the deformation of the surrounding rock. The initial support strength of the roadway is low, and the anchor rods and cables have not effectively played their active support role. Under high stress, the integrity and strength of the surrounding rock continue to weaken, resulting in gradual instability and failure of the full section roadway from shallow to deep. This reveals that the key to deformation control of high stress soft rock roadway lies in building a stable anchoring bearing structure. Based on this, the full section anchoring and grouting support technology is proposed, which improves the integrity and strength of the surrounding rock through grouting modification. The bottom plate grouting and anchoring achieve full length anchoring with internal anchoring and external grouting. Combined with the active support effect of the anchor rods and cables, a high prestressed anchoring and grouting bearing area is formed to improve the overall structural stability of the roadway. The underground application effect shows that after grouting modification, the integrity of the surrounding rock structure is significantly improved, the surface displacement of the roadway surrounding rock is significantly reduced, and the deformation of the bottom plate is effectively controlled, achieving good deformation control effect of high stress soft rock roadway.

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