Recently, as the shield machine cutterhead slowly rotated forward, the left-line shield of the Guangzhou Road Station–Tanggu Station section of Civil Construction Section 8 of Tianjin Rail Transit Line B1 successfully launched, marking that the Guang–Tang section has officially entered the shield tunneling stage.

Left-line shield of the Guangzhou Road Station–Tanggu Station section successfully launched

The Guang–Tang shield section of Rail Transit Line B1 is about 775 m long and is constructed by the shield method. The right line of the Guang–Tang shield section has already been completed, and the left-line shield machine completed shield transfer, lowering into the shaft, installation, commissioning, and acceptance in 22 days. The left line of the section starts from Guangzhou Road Station and runs along Hebei Road, successively crossing under the Jintang Highway Viaduct, the Jinbin Light Rail Line 9 Viaduct, and numerous municipal pipelines before reaching Tanggu Station. The strata traversed by the section are mainly silty clay and silty clay.

To ensure this smooth launch and accomplish the task objectives with quality and quantity, the project department strictly implemented the leadership shift system, advanced refined project management, and ensured that all construction links were safe, efficient, and orderly; it organized and worked with the design institute and industry experts to continuously optimize the special construction plan and emergency plan; and it held daily shield production safety meetings to ensure the successful completion of the node objectives of the Guangzhou Road Station–Tanggu Station section.

On July 29, the "Pioneer" shield machine for the right line of the Xinjiayuan West Station–Guoxiang West Road Station section of Rail Transit Line B1 successfully launched. This section welcomed another milestone node and entered a more critical construction stage.

Right-line shield of the Xinjiayuan West Station–Guoxiang West Road Station section successfully launched

The Xin–Guo section is about 2,695 meters long. Starting from Xinjiayuan West Station, it runs southward, successively passing beneath Xinjiayuan South Road, the Beijing–Tianjin Expressway, Gangcheng Avenue, the Zhonggangcheng Building Materials Market, the North Ring Railway, and the Beijin Connecting Line, and finally reaches Guoxiang West Road Station.

For the underpassing of underground pipelines and structures, the rail company organized the project team to conduct comprehensive investigation and risk assessment of the structures to ensure the accuracy of deformation control indicators; strengthened the management of tunneling parameters and precisely controlled the shield attitude; and strictly monitored data to provide timely information for construction safety and stability and a basis for further measures.

In addition, during tunnel construction, the project team refined the engineering design. For complex geology such as silty clay interbedded with silty sand, they optimized the cutter configuration and adopted a muck conditioning system and a bentonite and mud system to reduce wear risk; the double gates and wear-resistant design of the screw conveyor prevent gushing and ensure smooth muck discharge; the high-precision control of the segment erector improved assembly quality and speed; the active articulated shield body adapts to small-curve construction and improves attitude control; the specially designed screw conveyor discharge port and standby grouting pipes address water-rich strata and soils with poor self-stability; the remote monitoring system enables real-time monitoring, and the advance grouting hole design reinforces the geology. Through a series of measures, a solid guarantee was provided for the safe and efficient tunneling of the shield machine.

With the smooth advancement of the two shield tunnels, the construction pace of Rail Transit Line B1 will be further accelerated. Next, all rail transit staff will continue to work steadily and collaborate efficiently, keep a close eye on all construction nodes, and go all out to promote the high-quality development of rail transit in the Binhai New Area.