双层注浆小导管在隧道洞口工程中应用探讨

Application of Double Small Duct Grouting in Tunnel Portal Engineering

双层注浆小导管超前支护作为一种围岩加固措施,其在实际工程应用中有着很好的支护效果,因而在隧道开挖施工中逐渐被大量选用,尤其在山岭隧道超前支护中应用更为广泛。以实际工程为研究背景,针对双层注浆小导管超前支护加固的施工工艺及设计参数展开研究总结,并根据具体工程应用情况,与其他超前支护工法进行了对比分析。研究表明:双层注浆小导管超前支护施工机械简易,工艺简单,工法灵活,可根据开挖暴露的围岩随时调整支护参数,支护效果好,且经济性和实用性突出。本文的研究对双层注浆小导管超前支护在隧道洞口施工中的工程实践具有一定的指导意义。

As a kind of rock reinforcement measures,application of double small duct grouting pre support in the practical engineering has a good supporting effect. So it has been largely applied in the construction,especially in mountain tunnel support. Based on a actual project,double grouting pipe forepoling reinforcement construction technology and design parameters were studied and summarized,according to the specific engineering application,compared with other advanced support method. Research shows that: the double grouting pipe forepoling construction machinery is simple in process, flexible in method, supporting parameters can be adjusted according to the surrounding rock exposed at any time,good supporting effect,economical and practicality prominent. The research of this paper has certain guiding significance to the engineering practice of the double grouting small pipe advanced support in the tunnel entrance construction.