马湾隧道初支变形分析及处置技术研究

Initial Support Deformation Analysis and Disposal Technology of Mawan Tunnel

以软弱围岩特别是浅埋偏压、片理及节理裂隙发育、岩体破碎的隧道为研究对象,针对马湾隧道实际工程地质条件及隧道开挖、初支后产生的变形情况,分析原因,及时采取封闭掌子面、增设临时仰拱和加固环、对初支开裂严重部位和裂缝上下2m范围采取小导管注浆加固等有针对性的加固措施,有效的加固了隧道变形,确保了隧道的稳定性;根据试验段的结果和建议在后续的施工中调整支护参数,采用简单实用的"三台阶"施工工法,顺利进行了后续隧道施工。马湾隧道初支变形分析及处置施工等技术为相应软弱围岩隧道的施工意外情况处置提供了借签。

Taking weak surrounding rock, especially shallow buried bias, sheet and joint fissure development, rock fracture tunnel as the research object, in view of the actual engineering geological conditions and tunnel excavation of Mawan Tunnel, the causes are analyzed and targeted reinforcement measures including closing the tunnel face, adding temporary invert and reinforcement rings, adopting small catheter grouting reinforcement on the serious crack part and 2m over and below the crack are taken to effectively reinforce the tunnel deformation and ensure the stability of the tunnel. According to the results and recommendations of the experiment section, the support parameters in the follow-up construction are adjusted, and with the use of simple and practical ＂three steps＂ construction method, the follow-up tunnel construction is smooth. The analysis of the initial branch deformation and disposal of the Mawan tunnel provides a means for disposal of the construction of the corresponding soft rock tunnel.