黄土隧道短台阶仰拱连续施工技术

The continuous construction technology of short step inverted arch of loess tunnel

对蒙华铁路延安隧道开挖方法进行了研究,通过分析地质围岩情况,研究得出:隧道开挖将Ⅳ级围岩三台阶法调整为短台阶、仰拱连续施工开挖法。实现了上下台阶、仰拱同时爆破开挖、出渣、同时立架、喷混凝土,相同工序集中组织,减少了原三台阶法开挖施工的工序重复作业现象。隧道采用此方法具有工序衔接紧凑、机械利用率高、方便施工组织、隧道施工进度明显加快。

This paper researched the tunnel excavation m ethod,through analyzing the geological and surrounding rock situation,concluded that the tunnel excavation adjusted the grade IV surrounding rock three step method to short step,inverted arch continuous construction excavation m ethod,achieved the upper and lower steps,invert arch blasting excavation,slag tapping at the same tim e,and erect fram e,pneumatically placed concrete at the same tim e,centralized organized the same p rocess,reduced the working procedure repetitive operation situation o f original three step method excavation and construction.The tunnel adopted this method with com pact working procedure,high m echanical utilization,convenient construction organization,the construction progress o f tunnel speed up obviously.