On January 19, 2024, Shasan Station of the second phase of Shenzhen Metro Line 12 realized the full penetration of the large-section rectangular pipe jacking underground station, which marked a historic breakthrough in the field of urban rail transit construction by the key project of Guangdong Province led by Academician Chen Xiangsheng, president of our Institute. This is also the first successful practice of the super-large section combined rectangular pipe jacking construction technology in the world, which fills an important gap in the construction of mechanized subway underground stations in China, and has an important milestone significance in the history of subway station construction. FIG. 1 shows Academician Chen Xiangsheng, President of our College, participating in the receiving ceremony.

FIG. 1 Receiving ceremony of rectangular pipe jacking with the largest section in the world

The key project of "Modern Engineering Technology" of Guangdong Province Key Areas Research and Development Plan "Key Technology of Underground underground stations in Bustling urban Areas" is led by Chen Xiangsheng, academician of the Chinese Academy of Engineering and President of our College, and Shenzhen Metro Group Co., Ltd. as the lead unit. Joint Shenzhen Municipal Design and Research Institute Co., LTD., China Power Construction South Construction Investment Co., LTD., China Water Resources and Hydropower 11th Engineering Bureau Co., LTD., China Railway Engineering Equipment Group Co., LTD., Research and Design Institute of Railway Academy (Shenzhen) Co., LTD., Guangzhou Golden Earth Geotechnical Engineering Co., LTD., China Railway Construction Heavy Industry Group Co., LTD., and Nanjing Peguang Smart Sensing Information Technology Co., Ltd. and other units aimed at systematically exploring the green, efficient and intelligent mechanized underground excavation construction technology of subway stations.FIG.2 is the real shot of Shasan Station after the double holes were successfully completed.

FIG. 2 Shasan Station through the double holes

 Shasan Station, located at the intersection of Ditang Road and Shajing Road, is an underground two-story island platform station. The station is located in a bustling area of the city with numerous buildings around it. The soil in the area where the station is located is relatively loose and the groundwater resources are abundant. There is also a new large rain water tank culvert buried 4.2 meters deep below the station site. The station adopts a single-column, double-span frame structure with a total length of 208 meters and a standard section width of 23 meters. If the traditional open-cut construction technology is used, it will face a huge challenge of traffic removal difficulty, need to carry out a large number of buildings to relocate, invest a large number of labor, and also face a series of major problems such as high project risk, long construction period and complex construction conditions. FIG. 3 shows the interview of Academician Chen Xiangsheng, President of our College.

FIG. 3 Academician Chen Xiangsheng is interviewed by journalists

In order to cope with the above challenges, Academician Chen Xiangsheng, president of our Institute, led the research team to carry out collaborative research. In terms of theory, a complete set of design theories and methods of mechanized underground underground subway station are proposed, the mechanical characteristics of multi-hole combination jacking pipe and station structural system transformation are revealed, and a comprehensive risk assessment system of underground underground subway station construction is established. In terms of technology, the focus has broken through key technologies such as new underground excavation construction equipment and supporting construction, and developed the rectangular pipe jack with the largest section (11.29 meters wide and 13.55 meters high) in the world - "Dayu Drilling". The machine adopts the combination arrangement of multiple cutters and multiple screw machines, and through the collaborative operation of multiple cutters and screw machines, it has achieved a major breakthrough in the construction equipment technology of the balance of water and soil pressure on the ultra-high palm surface and the zero gap between the left and right two times. At the same time, a complete set of excavation construction technologies of micro-step, shallow soil cover, large section and zero gap were also established to overcome a series of major technical problems such as assembly of super-large section pipe joints, deformation control of underground box culverts, linear control of left and right lines closely attached construction tunnels, and surface settlement control, etc., to ensure the safety and efficiency of station construction. FIG.  4 shows the scene when Da Yu was digging the hole.

FIG.  4 shows the scene when Yu the Great dug the hole

The research team also established an intelligent monitoring system for the whole life cycle of station construction and operation and maintenance integrating multi-source sensing technology. Through the information intelligent management platform, the whole process of real-time information intelligent monitoring and management with the functions of information management, risk assessment and intelligent early warning is realized. This system provides comprehensive intelligent monitoring and management for station construction and later operation and maintenance, and guarantees the safety of the whole life cycle of the station.

Academician Chen Xiangsheng, president of our College, pointed out in an interview with a number of media that: compared with open excavation construction, the successful implementation of mechanical excavation technology has remarkable results, including a 35% reduction in carbon emissions, a 15%-20% reduction in construction time, a 40% reduction in earthmoving, a 20% cost savings, and the first time to realize the industrialization of subway station construction. The successful application demonstration of the new set of mechanized underground excavation technology in this project marks a comprehensive jump in the engineering theory, key technology and equipment manufacturing capacity in the complex environment of underground excavation construction in prosperous urban areas in China, leads a major change in the construction technology of subway stations, and greatly promotes the comprehensive progress of low-carbon, intelligent, efficient and safe development technology of urban underground space. FIG. 5 shows the scientific research team of our College taking a group photo at the receiving ceremony site.

FIG. 5 The team of Future Underground City Research Institute participated in the receiving ceremony at the site