Recently, the first permanent temporary integrated prefabricated diaphragm wall of an underground station in China was successfully installed in Xichong Station of Shenzhen Metro Line 8 Phase III Project of China Railway First Bureau, marking new progress and achievements in green and low-carbon construction technology exploration in the field of deep foundation pit engineering of the subway, and bringing new breakthroughs in the practice of "new quality productivity" in urban rail transit construction, This practice has laid a good foundation for similar projects in the future.

It is understood that the permanent temporary prefabricated diaphragm wall of Xichong Station, Phase III of Shenzhen Metro Line 8, is not only the foundation pit enclosure structure in the construction phase, but also serves as the side wall of the station's permanent structure. It realizes the innovation that the side wall of the main structure is permanent and temporary, and the two walls are integrated. Its wall has a huge size, 0.85m thick, 22.48m deep, 3m wide, and a single weight of 138.68t. The diagonal error of component fabrication shall be less than 1.5mm, and the installation error shall be less than 5mm.

It is reported that this highly difficult project is the first in China and faces many challenges, such as the production of super long and overweight precast concrete walls, high requirements for installation accuracy, high risk of aerial overturning and hoisting, and complex multiple waterproof treatment processes. The implementation of this scheme has made a creative breakthrough in realizing "zero" temporary projects and "zero" waste projects, and achieved a phased victory in energy conservation and emission reduction, green and environmental protection construction, etc.

Xichong Station of Shenzhen Metro Line 8 Phase III is located in Xichong Community, Dapeng New District, Shenzhen. It is the first subway station in Dapeng New District, and is a standard two-layer station structure. Up to now, 90% of the construction of the main structure of the station has been completed, and the construction of the internal structure of the station, the foundation pit retaining structure, and the entrance and exit accessories is being carried out in an orderly manner. After completion, it will be put into operation with Phase I, Phase II, and Phase III of Line 8, and effectively connected with Phase I of Line 32. It will become a backbone rail transit line connecting Nanshan, Futian, Luohu, Yantian, and Dapeng. It effectively serves the main commuter flow of Dapeng and Yantian, and takes into account the tourist flow of the eastern coastal areas. It will greatly improve the accessibility of tourists in Dapeng New Area. (Qiu Quanlin, Guangdong reporter station of China Daily)