Core Points - The Beijing Urban Sub-center Station Comprehensive Transportation Hub is the largest underground transportation hub in Asia, with a total construction area of 1.28 million square meters, exceeding the size of seven Beijing South Railway Stations [1][4] - The hub integrates two intercity railways, four urban subways, one suburban railway, and 15 bus lines, with a reserved space for a future dock [1] - The construction method used is called "cover-excavation reverse construction," where the roof is built first before excavating downwards, resulting in an earth excavation volume of approximately 14 million cubic meters [1][2] Construction Technology - Advanced technologies such as BIM (Building Information Modeling) and robotic equipment are employed to enhance construction quality and efficiency, achieving precision and increasing productivity by 6 to 7 times compared to traditional methods [2] - The hub's steel structure requires 35,000 tons of steel, with a welding task involving up to 35,000 weld seams, and welding robots are utilized to ensure "zero defect" quality [2] - The "Jingfan" roof design features a special ETFE membrane that allows light while preventing direct sunlight, contributing to a comfortable underground lighting environment [2][3] Energy Efficiency - The "Jingfan" roof includes perforated shading panels to balance thermal loads and control light transmission, reducing annual thermal load by 5.2 million kilowatt-hours, equivalent to the cooling capacity of 3,200 household air conditioners [3] - The hub is expected to reduce lighting electricity consumption by approximately 486,000 kilowatt-hours annually [3] Accessibility - The transportation hub is located in Tongzhou District, Beijing, and is expected to be completed by the end of the year, featuring over 150 entrances, with 60 directly connected to surface buildings for seamless access [3]