On August 26, 2025, the pipe jacking machine “Triumph” for the parking line of Huajiachi Station of Hangzhou Metro Line 18 Phase I was successfully launched, marking that the first rectangular pipe jacking machine with oversized section was formally applied in the construction of metro parking line. As a technical support unit of Shenzhen University, our academy's president, academician Chen Xiangsheng, led the pipe jacking scientific research team, which is making every effort to tackle the key technical problems of long-distance jacking construction of deep-buried oversized rectangular pipe jacking in the soft soil layer with high water pressure, to provide an important guarantee for the smooth progress of the project.

Hangzhou Metro Line 18 Phase I project, is the key line of Hangzhou rail transit. It starts from Xiaoshan Yiqiao Station in the south and ends at Linping Century Avenue Station in the north, with a total length of 48.3 kilometers, all of which are underground lines. Along the line set up 19 stations, of which 15 for the transfer station, with a number of lines transfer. 18 Huajiachi station is located in the intersection of Kaixuan Road and Huaji South Road, for the 18 line and the same period of 15 line “T” type transfer station, respectively, the addition of a length of 252 meters, 207 meters, width of 12 meters, height of 8.7 meters, two rectangular top tube parking line The two rectangular top tube parking lines are 252 meters long, 207 meters wide and 8.7 meters high, facilitating the daily scheduling of subway trains.

As it is located in the city center and the surrounding neighborhoods are dense, in order to minimize the impact of the subway construction, Huajiachi Station introduces a rectangular pipe jacking machine with extra large cross section, which is supported by “customized technology, low-disturbance process, and high safety standards”, and can be adapted to the complex geology and urban environment to reduce the disturbance to the surrounding strata and minimize the impact on ground buildings, underground pipelines, and road traffic during the construction period. During the construction period, it minimizes the impact on ground buildings, underground pipelines and road traffic. Meanwhile, through the integrated system design, the pipe jacking machine can take into account the efficiency and space utilization, and has the advantages of high construction safety and reliability, low comprehensive cost, high space utilization rate, and significantly shorten the construction period.

The “Triumph” pipe jacking machine with a section width of 12.02 meters and a height of 8.72 meters, the whole machine includes excavation system, drive system, shield system, slag discharge system, jacking system and after supporting system, etc. It adopts the design of 4-front and 4-back multi-tool discs with low-disturbance excavation, the design of multi-screw machine with anti-surge sealing system, the design of main drive to resist high water pressure and the design of shield support system adapted to large burial depth, etc. It is an “underground giant” tailor-made for the complex geological conditions in Hangzhou. Adapted to the design of shield support system for large depth, it is an “underground giant” tailor-made for the complex geological conditions in Hangzhou, which is the first time that rectangular pipe jacking machine is applied to the construction of large depth and high hydraulic pressure subway parking line.

The rectangular pipe jacking project for the parking line of Huajiachi Station faces many challenges: soft soil, high water pressure (0.3 MPa), large burial depth (22 meters) and long-distance jacking (252 meters), which are the first in the domestic rectangular pipe jacking project in terms of each index. There is an urgent need to solve the key technical problems such as high-precision control of pipe jacking attitude in soft soil, sealing of pipe jacking machinery and cave door under high water pressure environment, drag reduction for ultra-long-distance jacking and construction disturbance control.

In order to solve the above problems, academician Chen Xiangsheng, president of the academy, acted as the technical person in charge, and China Railway 10th Bureau, together with Shenzhen University, China Railway Equipment and other units, set up a research team and undertook the research and development task of the major special project of China Railway Corporation Limited, “Research and Application of New Technology of Micro-disturbance and High-precision Roofing of Extra-large Sections of Assembled Tunnels”. Hangzhou Metro Huajiachi Station Parking Line Project is one of the demonstration projects of this project.

This project is the first time that rectangular pipe jacking technology is applied to the construction of metro parking line in China, which reflects the further popularization and application of rectangular pipe jacking key technology research and development in the Guangdong Province key research and development program “Key Technology of Metro Concealed Excavation Stations in Busy Urban Areas” undertaken by Academician Chen Xiangsheng. The successful launch of “Triumph” means that the demonstration project of China Railway's major special project “Research and Application of New Technology for Micro-disturbance and High-precision Jacking Construction of Super-large Sections of Assembled Tunnels” has formally entered into the implementation stage, which demonstrates that China's theoretical research in the field of rectangle jacking pipe has realized a new level of technology development and equipment manufacturing, technology development and equipment manufacturing has achieved a new breakthrough, and promoted the construction technology of rail transit to take a key step in the direction of mechanization and intelligence.