超前管棚支护在浅埋偏压黄土隧道施工中的应用

摘要

A pipe-roof assisted by cement grouting is an effective way of providing advanced support for tunnel sections with special geological conditions, such as sandy soil, loess, crack development in stratum, shallow depth or bias stratum. This paper introduces the construction technology, processes and technical characteristics of the pipe-roof used in certain shallow-buried and bias loess tunnels. The reliability of the pipe-roof is ascertained based on the analysis of monitoring data. Engineering practices showed that the pipe-roof effectively reduced surface subsidence and rock deformation and guaranteed safe construction of the sections with adverse geological conditions.%在特殊地质地段,如砂土地层、黄土地层、裂隙发育地层、浅埋地层、大偏压地层等隧道围岩地层中,采用超前管棚支护并辅以水泥注浆,是一种行之有效的超前支护方法.文章介绍了某浅埋偏压黄土隧道超前大管棚的施工工艺、流程及技术要点,并通过监控量测的数据分析,证明了该方法的可靠性.工程实践表明,超前管棚支护有效地减小了地表下沉和围岩变形,达到了确保不良地质段安全施工的目标.