Shengli Connection of No.2 Inclined Shaft and No.3 Cross Tunnel of Xiaosanxia Tunnel on Zhengzhou-Wanzhou Railway

The reporter learned from the construction headquarters of Fengjie Section of Zhengzhou-Wanzhou High-speed Railway that at 8:08 on August 27, the No.2 inclined shaft of the Xiaosanxia Tunnel of Zhengzhou-Wanzhou Railway crossed with No.3 transverse tunnel, marking the successful crossing of the first main tunnel of the Xiaosanxia Tunnel, which is 18.954 kilometers long, and offering a great gift for the 70th anniversary of the founding of New China. The total length of inclined shaft No. 2 and section No. 3 of Xiaosanxia Tunnel is 2950m, and the fighting lasts 850 days. The cave body of this section is affected by many back and synclines, and the interfacial wavy undulations of rock layers are mainly manifested in the lithological changes of strata caused by the undulation of bedrock, the softening of mudstone, the deformation of rock mass caused by the unsymmetrical pressure of bedding or the stress release of gently inclined strata, etc. The site is all grade IV and V surrounding rocks. The construction organization is difficult, the safety risk is high, the technical management is strict, and the construction production and construction organization are facing great challenges.

"The successful connection of No. 2 inclined shaft and No. 3 horizontal tunnel of the Small Three Gorges Tunnel is only a stage achievement of the safe and smooth connection of the whole tunnel as soon as possible, but not the final victory." According to the relevant person in charge of the project, the connection of the tunnel has greatly improved the ventilation, traffic and drainage conditions at the outlet of the main tunnel. It is of great significance for further releasing resources, reducing the difficulty of construction management, realizing the full connection of the small Three Gorges tunnel as soon as possible and removing the construction alarm of the ultra-high risk tunnel. Up to now, 15439 metres of auxiliary tunnels have been completed for the small Three Gorges Tunnel. The main tunneling of the small Three Gorges Tunnel has exceeded 14460 metres, totaling 76.28 percent of the total length of the tunnel of 18.95 kilometres.
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