Recently, the Tianjin Jingbin Intercity Railway Section 4 (Phase II) project, in which Shanghai Yuanfang participated in construction, was successfully completed and received full recognition from the client. During construction, the project team carried out each process with the utmost care, always upholding a work spirit of focus and professionalism, meticulous execution, and diligence and pragmatism to advance construction work in an orderly manner, achieving excellent results in many aspects such as overall project operation, safety management, quality control, and cost control.

 Guide wall construction 

In this phase, Shanghai Yuanfang was responsible for the construction of the retaining structure for No. 2 shaft and the shield receiving end structure area of No. 2 shaft. The No. 2 shaft and single-layer section diaphragm walls total 57 panels, of which the No. 2 shaft diaphragm wall totals 15 panels, with a wall depth of 62 m and a wall thickness of 1.5 m. The single-layer section diaphragm wall totals 42 panels, including 26 Type B diaphragm wall panels with a wall depth of 52.3 m and a wall thickness of 1.2 m, and 16 Type C diaphragm wall panels with a wall depth of 56.1 m and a wall thickness of 1.2 m.

At the shield receiving end of No. 2 shaft, plain concrete diaphragm walls are used for reinforcement on the outside, and RJP high-pressure jet grouting piles are used for full-area reinforcement on the inside. The plain wall has a total length of 65.3 m and a width of 1.0 m; the reinforcement depth of the plain wall is 36.5 m, and the total volume of the plain wall is 2383.45 m3. The plain wall adopts flexible locking pipe joints.

The plain wall was originally divided into 11 panels and later adjusted to 8 panels: among them, 6 are straight "I"-shaped panels, with panel widths of 8.2 m (4 panels)/8.65 m (2 panels); 2 are "L"-shaped panels, with a panel width of 7.6 m.

 Rebar cage fabrication and acceptance  

 Slurry works  

The project is close to the Bohai Sea, and the water quality in the construction area is seawater. Seawater causes severe slurry separation, making slurry preparation very difficult. After numerous tests and repeated adjustments, the project team of the Tianjin Jingbin Intercity Railway Section 4 project successfully overcame the difficulty of slurry formulation and ensured smooth slurry preparation during construction. In addition, because the construction area is only 4 km from Tianjin Binhai International Airport, the construction work height within the site is limited to 45 m, making lifting operations relatively difficult. After thorough planning, the project team adopted the solution of lifting and fabricating the rebar cages in 2-3 sections and lowering and lifting them as a whole after splicing was completed to solve the problem of site height restrictions. Through scientific planning and reasonable construction arrangements, the trench wall stability and trenching verticality were properly controlled, avoiding quality hazards such as collapse, hole shrinkage, and trench deviation.

Trench wall inspection record  

When encountering construction difficulties, the project team did not fear or shrink from them, but rose to the challenge and took the initiative. At the same time, in the process of solving construction difficulties and overcoming technical problems, the project team continuously summarized experience, optimized and innovated construction techniques, thought carefully and made sound decisions, and advanced with dedication, fully demonstrating the Yuanfang spirit of striving ahead and pioneering innovation.