Hangzhou Metro construction has achieved another new milestone. Recently, as the cutterhead of the "Qinlong No. 32" shield machine began to rotate,the right-line tunnel of the section between Longteng Street Station and Zhanjiaqiao Road Station on Section SG15-15 of Hangzhou Metro Line 15, constructed by China Railway Seventh Group, was successfully launched,marking the project's full entry into the fast track of dual-line tunneling and laying a solid foundation for the subsequent breakthrough of the section tunnels.

It is understood that the right-line tunnel of the section between Longteng Street Station and Zhanjiaqiao Road Station on Hangzhou Metro Line 15 has a total length of 768.2 meters. A composite earth pressure balance shield machine is used for construction, with a cutterhead excavation diameter of 6.47 meters.

Both the left and right lines are launched from the large-chainage end of Longteng Street Station,

bored in the northeast direction, and finally received at Zhanjiaqiao Road Station.

According to the introduction, throughout the entire tunneling process, the minimum curve radius of the section is 380 meters, which places high demands on tunneling control and segment selection. During shield tunneling, the shield machine needs to pass through strata such as silty clay interbedded with silt

and mucky clay.The tunneling route needs to pass beneath more than ten major risk sources, including Yangjiabang Bridge, Siwei Village Cultural Hall, Hengshi Road Chongwen Street, the Nanjing-Hangzhou High-Speed Railway, Yanqiao Pumping Station, Zhanqiaogang River, Chongxian New Town D-5 Affordable Rental Housing,

and Zhanqiao Xinyuan Residential Community.

In addition, during tunneling, it is necessary to overcome the technical challenge of cutting through pile foundations of the pile-slab structure beneath the municipal road under the Nanjing-Hangzhou High-Speed Railway—8 piles on the left line and 9 piles on the right line—which imposes extremely high requirements on construction precision and safety control.

To ensure safe and smooth shield tunneling, the project department deployed in advance and made meticulous plans, conducting comprehensive investigation and in-depth analysis of the geological conditions of the crossing section and data on surrounding buildings and structures, and formulated

detailed construction plans and emergency response plans,

making every effort to ensure that the entire construction process proceeds safely, smoothly, and efficiently.