吕临铁路前陡泉隧道横洞转正洞施工技术

On construction technique for reconstruction of transverse tunnels into main tunnels at Qiandouquan Tunnel along Lvliang-Linxian Railway

结合前陡泉隧道工程实际条件,详细介绍了隧道横洞转正洞"小导洞扩挖法""大包法"两种施工技术方案,并对挑顶技术、初期支护参数确定以及施工注意事项作了论述,通过实践,得出了一些有意义的结论。

Combining with the factual conditions at Qiandouquan Tunnel project,the paper mainly introduces the comparison between two con-struction schemes for the reconstruction of transverse tunnels into main tunnels,the small pilot drift expanding excavation method and full-enve-lope method,indicates the roof brushing,primary support parameter identification and construction precautions,achieves some meaningful conclu-sion by practice.