Airport Link Section 3 Project
The third section of the airport connecting line project includes the starting shaft of the Meifu Road shield tunneling and the 3 # air shaft, with a total length of approximately 7.855 kilometers for the shield tunneling section. Among them, the section from Meifu Road working shaft to 3 # air shaft to 2 # air shaft tunnel has a total length of about 5.685 kilometers, and the shield tunnel from Huajing Station to Meifu Road working shaft has a total length of about 2.17 kilometers, which are respectively excavated and constructed by two 14 meter super large shield tunneling machines, "Jiyue" and "Qiyue". The excavation diameter of the interval tunnel reaches 14.07 meters, and it adopts a single tunnel double track section layout. The outer diameter of the tunnel structure is 13.6 meters, and the inner diameter is 12.5 meters, and staggered joint assembly is used.
Since its departure on October 21, 2022, the "Jiyue" shield tunneling machine has overcome the complex construction environment, diverse geological types, and difficulties in crossing existing railways and rail transit during the excavation process. Finally, it was successfully received at the 2 # air shaft. One of the highlights of the "Jiyue" shield tunneling machine during excavation construction is its use of synchronous push and assembly technology with ultra large diameter shield tunneling. The synchronous push and assembly technology used by the "Jiyue" shield tunneling machine this time, based on thrust vector control technology, successfully integrated the segment assembly into the excavation operation, paralleling the excavation and assembly links. While ensuring the stable excavation posture of the shield tunneling machine, the assembly machine achieved simultaneous segment assembly, effectively improving construction efficiency.
Shanghai Tunnel has long-term experience in construction of ultra large diameter shield tunneling and a good awareness of shield tail protection. In addition, we have actively developed the most suitable grease injection plan through years of cooperation with our company, and have always controlled the amount of grease in an economical and safe range during the construction process, laying a good foundation for the safe connection of the entire tunnel.
After the connection, when the shield tail was pushed out, our technical personnel also rushed to the site at the first moment to check the situation of the shield tail brush. After long-distance construction, the overall tail brush of the shield still maintained a certain degree of angular elasticity, and there was still some grease inside the included angle part, without slurry agglomeration.
Sincerely thank Shanghai Tunnel for providing us with this cooperation platform, and we look forward to further cooperation with Shanghai Tunnel in various fields of tunnel development in the future!