既有铁路隧道扩挖施工技术

Expanding Excavation Construction Techniques for Existing Railway Tunnels

东北地区有大量解放前后修建的铁路线路,这些铁路线路上的铁路隧道,断面小,标准低,只能行驶内燃机车,需对既有铁路隧道进行原位改扩建。以沈丹铁路福金岭隧道原位扩挖为切入点,介绍了不同围岩级别下隧道扩挖采取的施工工艺、方法,对比新建隧道与改扩建隧道施工难易程度和造价情况。研究显示,既有隧道扩挖施工地质风险较小,控制爆破要求高,扩挖隧道相对新建隧道造价低,环境影响小。老旧隧道的改扩建具有现实经济意义。

There are a large number of railways built before and after the liberation in the northeast regions of China,of which the tunnels are of small cross-sections and low standards,in which case they can only allow diesel locomotives to pass through and thus In-situ reconstruction and expansion of those existing railway tunnels are necessary.With the in-situ excavation of the Fujinling Tunnel of Shen-Dan Railway as the breakthrough point.Introduced in the present paper are the construction techniques and methods applied to the expanding excavation of railway tunnels in different grades of surrounding rock,with the difficult degrees and different costs of newly-built tunnels and the expansion of existing tunnels compared.Our research shows that the geological risk in the expanding excavation construction of existing tunnels is smaller,the control blasting requirements of the expanding excavation of existing tunnels are higher,and the cost of the expanding excavation of existing tunnels is relatively lower than those of the newly-built tunnels,and the environmental impact is also less than that,according to which it can be concluded that the reconstruction and expansion of the existing tunnels are of practical economic significance.