Recently, the construction of the Qingdao Metro Line 8 Branch has made new progress: the 11 shield tunneling machines required for the line provided by CCCC Tianhe have all been delivered as of now. The 8th shield tunneling machine, "Jiaozhou Bay No. 8," has successfully launched. The launched shields have cumulatively excavated over 5,200 meters, marking a new stage of accelerated shield tunneling construction.

"Jiaozhou Bay No. 8" is a composite earth pressure balance shield tunneling machine with an excavation diameter of 6.5 meters, a total length of about 100 meters, a total weight of about 600 tons, and a maximum thrust of 4,160 tons. It adopts the steel sleeve launching and receiving process and is responsible for the 1,466-meter tunneling task in the section. The strata it passes through are mainly silty clay, coarse sand, strongly weathered mudstone, strongly weathered argillaceous siltstone, moderately weathered argillaceous siltstone, and moderately weathered mudstone, with poor geological conditions and high construction difficulty.

To ensure that "Jiaozhou Bay No. 8" smoothly completes the tunnel, the company's design team carried out special design for the cutterhead to prevent mud cake formation, increasing the central opening rate to over 40%, and equipping it with a muck conditioning system and cutterhead cleaning and injection devices. Before the shield machine takes in mud and stone, it soaks the front working face to make it loose, allowing the shield machine to "brush its teeth and rinse its mouth" while tunneling, so that the shield machine has no chance of being "stuck by teeth," avoiding mud cake formation during tunneling. At the same time, the company has also equipped the project with a skilled support team to provide on-site support services around the clock, make advance predictions, analyses, and control of fault risks, and ensure high-quality construction of the project.

The Qingdao Metro Line 8 Branch starts at Dajian Station and ends at Jiaozhou Railway Station, with a total length of about 20.4 kilometers and a designed maximum speed of 120 km/h. It is a rapid corridor serving the passenger flow corridor between the Jiaozhou cluster and the Hongdao Economic Zone, the Airport Economic Zone in the north bank urban area, and the east bank urban area. After the line is completed, it will accelerate the integration process between Jiaozhou and Qingdao's main urban area and help Jiaozhou enter Qingdao's "one-hour living circle."