宝峰隧道下穿既有线铁路隧道施工技术

宝峰隧道全长7377m,是昆明至河口铁路昆阳至玉溪段重点控制工程,出口段在D2K17+615处下穿既有昆玉铁路,洞口离既有铁路50m,隧道顶部距离既有铁路路基27m。隧道施工难点为下穿既有铁路施工期间不可影响既有线正常运营,施工难且风险大。本次浅埋隧道穿越既有铁路施工,通过采用合理的施工工法,超前加固,加强初期支护,严格控制沉降,达到了保证既有线路的安全和行车安全,顺利通过下穿既有线段的目的。

Tunnel Treasure Peak Tunnel in the Existing Railway Tunnel Construction Technology

Baofeng Tunnel total length is 7377m, it is the one of the key part between Kunyang and Yuxi of the rail- way which is from Kunming to Hekou. The exit zone （D2K17＋615） is under-passing the Kunyu Railway, its tun- nel front is 50m far from the railway and 27m high from subgrade of that. It is difficult to build up a tunnel under- pass an existing railway without affecting its normal operation. For ensuring both line safety and traffic safety and achieving the success of this tunnel construction, some key points the author points out as follow. Firstly, doing rein- forcement in advanced. Secondly, have a reasonable construction technique during the whole construction. Thirdly, strengthen primary support. Finally, control the settlement strictly.