SHENZHEN,June 15(Xinhua) -- The Lishan Station of Shenzhen Metro Line 27 was topped out on Sunday with the installation of its final prefabricated roof slab, marking the completion of the country's first subway station built with a secant pile support system and a fully prefabricated flat-roofed pillared structure.
The first phase of Shenzhen Metro Line 27 has a total length of 25 kilometers and includes 21 stations. As a key livelihood project and comprehensive transport hub for the city, it plays a significant role in improving the regional rail transit network, enhancing travel efficiency for residents, and promoting coordinated development among districts.
The Lishan Station, which was constructed by China Railway 25th Bureau Group Co., Ltd., is situated in complex geological conditions featuring thick water-rich sand layers and dense boulder distributions, with high groundwater storage, rapid seepage, and extremely poor soil stability. The surrounding area is densely packed with buildings and intricate underground pipelines, presenting considerable construction challenges. To address these difficulties, the project team adopted a full-casing secant pile support system, which forms a closed continuous water-stop curtain through tight interlocking between piles. This approach effectively solved industry-wide problems such as leakage in water-rich foundation pits and structural deformation control, achieving the first enclosed retaining structure for a station on the entire line.
In terms of structural construction, the station innovatively employs a "prefabricated plus cast-in-place" rectangular frame system. All 331 prefabricated components were manufactured in factories to standardized specifications and then transported to the site for millimeter-precision assembly using a "building-block" modular method, establishing a new paradigm for domestic prefabricated flat-roofed pillared stations. To overcome the challenges of high-precision construction for large prefabricated components, the builders deeply applied BIM 3D modeling technology to create a digital model of the entire station, conducted virtual simulations for the entire process of component transport, hoisting and assembly, and deployed intelligent gantry cranes and high-precision assembly trolleys in coordinated operation, successfully achieving precise hoisting and alignment of large-volume prefabricated components.
"Compared with traditional construction methods, the innovative techniques used at Lishan Station have shortened the construction period by 30 percent and reduced dust pollution by 70 percent, while significantly lowering on-site wet work, construction noise and carbon emissions," said Liu Yuguo, chief engineer of the project. He added that these methods have effectively reduced the excavation depth of the foundation pit, comprehensively improved the structural integrity and waterproofing performance of the station, and minimized the impact on the surrounding ecological environment and daily life of nearby residents.
As a vivid practice of Shenzhen Metro's commitment to smart construction and green development, Lishan Station has provided a replicable and scalable "CRCC solution" for similar subway station projects across the country. Going forward, the project team will strictly adhere to safety standards and accelerate the remaining construction work on Shenzhen Metro Line 27, injecting strong momentum into the development of the "railway-based Greater Bay Area."
