January 26，Huge painting on a cutter head“”Yes“New journey number”The shield machine successfully rolled off the production line in China Railway Construction Heavy Industry，It will be applied to the construction of the Yangtze River Tunnel Project of Nanjing Metro Line 4 Phase II, the deepest river-crossing subway tunnel in the Yangtze River Delta.。

“New journey number”Jointly built by China Railway Construction Heavy Industry and China Railway 14th Bureau，Excavation diameter of shield machine 11.6 meters，Total weight 2100 tons，Total length 120m，High-precision gas-liquid pressure balance control technology equipped with excavation bin、High pressure flushing system、Automatic pressure balan technology for driving seal，Among“Ynchronous double-liquid slurry injection technology”It is the first application of river-crossing subway tunnel construction in China.，To improve efficiency，Ensure safety。Shield machine cutter head coating“”It means that the shield machine is like a general guard for the safe and smooth excavation of the tunnel.，Ensure the high quality of construction tasks、Efficient、Completed successfully。

The shield section of Nanjing Metro Line 4 Phase II Yangtze River Tunnel Project starts from the middle air shaft of Jiangxinzhou in Jianye District.，Under the Yangtze River levee of Jiangxinzhou，After passing through Qianzhou and the Yangtze River，Received at Binjiang Station of Jiangbei New Area，The total length of the line is 3062 meters.，It is designed as a single-hole double-track tunnel.，Inner diameter of segment 10.2 meters，Outside diameter 11.2 meters。The tunnel project crosses the Yangtze River for a long distance.，The lowest point is 68 below the surface of the Yangtze River..58 meters，It is the deepest subway tunnel across the Yangtze River in the Yangtze River Delta region.，Environmental protection requirements are high，The construction is difficult。Shield Tunneling across the Silty Clay in the Yangtze River Floodplain、Silty fine sand、Medium coarse sand、Round gravel formation，The biggest test is to cross the 600-meter-long moderately weathered argillaceous sandstone stratum.，Quartz content up to 90％，Maximum water and soil pressure up to 7.4 bar，Set the cutter head、The tool and circulation system are seriously worn.，Thrust on shield machine during tunneling、Torque、There are very high requirements for the stability of the tunnel face.。

After the completion of the second phase of Nanjing Metro Line 4, the core area of Jiangbei will be connected with the main city of Gulou in Jiangnan.，Greatly strengthen the linkage between the North and the South，It plays an important role in connecting the core area of Jiangbei New Area and the core area east of Zijin Mountain.。