双液回退劈裂注浆在胡麻岭隧道富水粉细砂地层中的应用

Application of Two-Component Backward Split Grouting to the Humaling Tunnel in Water-Rich Fine Sand

胡麻岭隧道富水粉细砂地层开挖后自稳能力极差,掌子面不稳定,易坍塌,经常出现底板冒水、涌砂、涌水、沉降、初期支护变形等现象。采用常规注浆,注浆量大、工效低,效果不明显;采用化学注浆,造价又过高。大量工程实践表明,采用双液回退劈裂注浆方案,有效地改善了地层的稳定性,控制了围岩变形,且降低了施工成本。

The excavation of the Humaling tunnel in water-rich fine sand was very unstable and inclined to collapse, resulting in water inflow, gushings, significant settlement, and primary support deformation. Conven-tional grouting usually consumes large amounts of grout and is relatively inefficient, while using chemical grout is expensive. Based on much practice, this study found that two-component backward split grouting effectively improved the ground stability and controlled the deformation of surrounding rock as well as influenced construc-tion costs.