On June 17, 2026, in Sanxing Town, Haimen, Nantong, the high-speed railway construction site was bustling with activity. All members of the construction team remained at their posts and successfully completed the pouring of the last top plate of the foundation pit in the core area of Haimen North Station after 24 hours of uninterrupted construction. This special land with soft geology and abundant groundwater has always been a key and difficult area for rail transit construction. The construction team faced world-class construction challenges and relied on intelligent construction technology to overcome the bottleneck of soft soil construction, successfully completing the construction of the main structure, marking a significant breakthrough for this super underground high-speed railway station.

Leading in scale nationwide

Haimen North Station is a key control project of the Shanghai Chongqing Chengdu high-speed railway and a rare large-scale underground high-speed railway hub in China. The station adopts a layout of two six line stations, with the first underground level serving as a transfer passage, the second underground level as a high-speed railway platform, and the third underground level reserved for intercity rail tracks. The north side of the station is connected to the planned Nantong New Airport, which will be developed into a comprehensive transportation hub integrating multiple modes of transportation in the future. The station has a continuous excavation length of 1.8 kilometers, with a maximum excavation depth of 29.4 meters and a total excavation volume of about 1.5 million cubic meters. It is currently the longest ultra deep and ultra large foundation pit underground high-speed railway station in China, equipped with a 1.2-meter diaphragm wall and 5 concrete supports.

Overcoming geological challenges

The station is located in a layer of rich water, silt, and silty clay soil, which is generally loose and soft. The construction conditions are extremely poor, and there is no international precedent for building an underground station with a speed of 350 kilometers per hour in this layer. The foundation pit has a first level safety rating, and the maximum horizontal displacement of the enclosure structure shall not exceed 5 centimeters. The surface settlement control value shall not exceed 3 centimeters, and the control standards are extremely strict. At the same time, the region has abundant groundwater, deep precipitation, a wide catchment area during the rainy season, and a high risk of sudden mud and water influx, making the overall construction difficulty unprecedented.

Intelligent escort construction

This project is jointly constructed by a professional team, and three sets of digital intelligent control systems are innovatively applied during the construction process. More than one thousand drainage wells have been set up on site to achieve precise zoning and on-demand precipitation, relying on automated equipment to complete water level and flow monitoring and early warning. Simultaneously set up 2185 monitoring points for foundation pits, establish a full process intelligent monitoring system, capture construction data in real time, predict safety hazards, and comprehensively ensure project quality and construction safety. At present, the project has bid farewell to the structural tackling stage and officially entered a new stage of mechanical and electrical installation and station building construction.Keywords: Shanghai Chongqing Chengdu High speed Railway, Intelligent Construction, Yangtze River Delta Integration

As a core component of the national high-speed railway corridor along the Yangtze River, the Shanghai Nanjing Hefei high-speed railway will connect the fast channels of the three major metropolitan areas of Shanghai, Nanjing, and Hefei, optimize the railway layout along the Yangtze River, and have important strategic significance for the development of the Yangtze River Economic Belt and the integration of the Yangtze River Delta.Editor/Li Xiaohua