Recently, the shield-driven upline of the section from Shida South Road Station to Dinggong Road North Station on Nanchang Metro, constructed by the Third Company of China Railway 18th Bureau Group, successfully passed beneath the Beijing-Kowloon Railway bridge, with train speeds limited to 45 km/h on the track during the underpass. As of now, all data indicators are good and the railway line is operating normally. This is the first time that Nanchang Rail Transit Line 1 has safely and successfully passed beneath an operating national trunk railway line in both directions.

 

　　To ensure construction safety, before the shield machine crossed beneath the Beijing-Kowloon Railway bridge, sleeve valve pipe grouting pre-reinforcement treatment was carried out on the bridge to enhance its overall stability. At the same time, protection and track surface monitoring were carried out above ground, while excavation parameters and surface and bridge structure monitoring were strictly controlled below ground. Close coordination between above-ground and below-ground teams ensured timely information exchange to guarantee the safety of the railway line.

　　

　　According to reports, this shield machine began its underpass of the Beijing-Kowloon Railway bridge at 8:00 on January 6. The Yongchang No. 2 shield machine faced risk sources such as a double-arch sewage culvert and high retaining walls right from launch, making it more difficult than the downline. During the underpass, train speeds on the track were limited to 45 km/h, and the machine successfully crossed beneath the Beijing-Kowloon Railway bridge on January 8. All data indicators are good and the railway line is operating normally. Currently, design and railway operation requirements are met. Shield team construction personnel will take measures such as secondary grouting inside the tunnel to continue reinforcing the bridge body, and will continue monitoring until the bridge body stabilizes. Next, this machine will continue advancing to pass beneath the Erqi Road Bridge, also located on Beijing Road. Currently, Yongchang No. 1 has completed 470 rings of excavation. It is understood that the section is expected to achieve bidirectional breakthrough by the end of February 2014.