The cross-river section of the airport link line of Shanghai City Railway was successfully completed

Recently, Shanghai Shentil is responsible for the investment and construction, and the tunnel section of the municipal railway airport link line from 5 Biao Huajing Station to Sanlin South Station constructed by Shanghai Tunnel shares has been fully completed. This is the only ultra-large diameter tunnel section of the airport connection line of Shanghai Municipal Railway crossing the Huangpu River, and it is also the second time that "Qiyue" completed the tunneling task of the tunnel section in the construction of the airport connection line.

The 5 tunnel section from Baohuajing Station to Sanlinnan Station is 4.28km long, with a total of 2141 loops, and the construction is carried out by the domestic 14.07m-class mud-water-air balance super-large diameter shield machine "Qiyue". The maximum slope of the tunnel section is +8.82‰, and the buried depth of the tunnel section is 31.16 meters to 47.50 meters. Since its inception on September 26, 2022, it has completed a 1.1-kilometer ultra-long underpass through the Huangpu River and a number of major risk sources, achieving an average excavation of more than 300 rings (600 meters) for four consecutive months and a maximum excavation of 323 rings (646 meters) in a single month.

The shield receiving construction is difficult, the construction period is tight, the risk is large, and the task is heavy. Under the overall deployment and advance organization of Shanghai Shentie, the project team and the participating units work together to strictly implement the requirements and actively coordinate resources, and finally ensure the smooth progress of the shield receiving work.

The shield receiving site is small, in order to complete the node goal, before the formal reception, the project team held a general disclosure of the shield receiving meeting, and worked together to refine the receiving process and the precautions of each step of the process, and the responsibilities were refined to individuals, so as to achieve accurate construction and real-time reporting, forming a closed-loop solution, and reducing the risk of shield receiving.

Due to the complex geological environment of the shield receiving, the project team continuously optimized the receiving work plan, and reduced the risk of tunnel door leakage by deepening the design depth of the dewatering well from 33.5 meters to 39.5 meters, lengthening the filter pipe to 37.5 meters, and increasing the number of dewatering Wells from 6 to 8. The measures of sealing the tunnel door twice are adopted to reduce the leakage risk of the tunnel door, the shell of the shield machine and the segment due to sudden clearance in the receiving process.

The top soil covering depth of the receiving section of the shield is about 24 meters, and the gap between the hole ring and the segment is relatively large, which increases the risk of leakage from the tunnel door. In view of this situation, the project team adopted the airbag receiving scheme, by embedding rubber air bags in the hole ring, after the cutter head through the hole ring, according to the actual situation of the field, the air bag is opened at any time, to block the gap between the hole ring and the shell, so as to form a safe and reliable barrier. During the assembly of the receiving section, sponge strips were installed on the whole circle of the back of the segment, and the amount of grease injected into the tail of the shield was adjusted accordingly to reduce the risk of leakage.