Recently，Earth pressure balance shield machine jointly built by China Railway Construction Heavy Industry and China Railway 14th Bureau“Yong'an No.1”Ningbo Rail Transit Line 7TJThe right line of Section 7026 started smoothly.。The excavation diameter of the EPB shield machine is 6.76 meters，The length of the whole machine is about 76 meters.，The weight of the whole machine is about 450 tons.，The installed power is about 1600 kW.。

“Yong'an No.1”Starting site of shield machine

Ningbo Rail Transit Line 7TJThe left line of the 7026 section is about 2884 meters long.，The right line is about 3284 meters long.。The shield machine mainly passes through silt.、Muddy clay、Silt and other strata，It is easy to cause the shield machine to float during construction.、The phenomenon of planting first class。The side of the line passes through multiple high-voltage electric towers.，Underpass 3 bridge removal and reconstruction areas、Four rivers、1 high-speed viaduct and 1 overpass，There are embedded piles during construction、Diaphragm wall and other obstacles，Difficult construction of shield machine。

According to the engineering characteristics of the project,，R & D technicians of China Railway Construction Heavy Industry Co., Ltd.“Yong'an No.1”Targeted design is carried out.。For example, external design is adopted for the grouting pipe at the shield tail.，Ffectively reduce that excavation diameter，The construction cost is reduced.；Targeted design of cutter head and its cutters and configuration of low-speed propulsion system，It effectively solves the construction problems of shield machine grinding pile and penetrating diaphragm wall.。

“Yong'an No.1”The shield machine is offline

Initiated this time“Yong'an No.1”The shield machine is responsible for the excavation of the right line from Minghai Avenue Station to Yufan Road Station.，Orderly cooperation between China Railway Construction Heavy Industry and China Railway 14th Bureau，Promote all kinds of work efficiently，It took only 18 days to complete the assembly of shield machines with high standards.、Commissioning work，It's a strong guarantee“Yong'an No.1”Smooth start of shield machine。