1 前言 现阶段山岭公路隧道浅埋段施工方法主要为明挖法和暗挖法,其中,暗挖法应用最为广 泛,但其要求隧道具有一定的埋深,若埋深太浅难以形成承载拱,围岩稳定性难以保证或施工成本过高,最终造成塌方。若采用明挖法进行施工,隧道两侧放坡开挖对周围环境破坏较大,且土方工程量巨大。盖挖法兼具上述两种施工方法的优点,能在保证施工支护安全的前提下减少对周围环境的影响,且能在短期内恢复地面交通,已被广泛应用于城市地铁工程,个别山区公路隧道浅埋段也已采用盖挖法进行施工并取得成功。
图4 土拱模机械初步开挖
图8 土拱模现场喷射砼硬化
图9 土拱模硬化成型
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|