On January 19, 2024, the equipment takeover ceremony was held at the site of the Shenzhen Subway Line 12 Project (Phase II). The dual-line tunneling engineering has been completed by adopting “CREG 1179” (“Dayu · Juejin”), the super-large cross-section combined rectangular pipe-jacking shield machine jointly developed by China Railway Engineering Equipment Group Co., Ltd. (CREG) under CRHIC and other units. It is the first time in the world that super-large section machinery is used in underground excavation of metro station, which is of revolutionary significance to the construction method of urban metro stations.

The platform station is 208 meters long, the single track of the jacking section which covers the left and right tracks is 70 meters, and the section of the formed station is 22.6 meters wide and 13.5 meters high. The earthing in the site is shallow, with abundant groundwater around it. And there is a newly built culvert below the site, thus facing such challenges as high relocation cost, difficulty in traffic relief and complexity in construction conditions.

In view of the complex construction environment of the Project, the research and development team of CREG has tailored the “Dayu · Juejin”, the super-large cross-section rectangular pipe jacking shield machine with a width of 11.29 meters and a height of 13.55 meters, which is composed of two sets of equipment, equipped with multiple cutter heads, and cooperatively controlled by several screw machines. Besides, the micro-step excavation technology and attitude measurement and control technology are adopted to effectively guarantee safety, high-quality and efficient construction of the Project.