On October 28, the "Chuxin" shield arrival and project breakthrough mobilization meeting of the Hangzhou Huancheng North Road-Tianmushan Road Road Upgrading and Reconstruction Project was held at the No. 2 working shaft site. The "Chuxin" large shield machine took 364 days to successfully break through the north line of Section 02 of the Tianmushan Project.

Yang Tieding, Deputy Director of the Hangzhou Municipal Construction Commission; Li Hongliang, General Manager of Hangzhou City Investment Group, and Shen Zhuoheng, Deputy General Manager; Xiong Yongguang, Deputy Head of the Municipal Quality and Safety Supervision Station; Wu Jian, Chairman of Hangzhou Urban Construction Development Group; and Zhang Yanwei, General Manager of the company, as well as leaders of other relevant units, attended the breakthrough mobilization meeting.

The Huancheng North Road-Tianmushan Road (Zhonghe Interchange-Gucui Road) Upgrading and Reconstruction Project is the middle section of Hangzhou's "four vertical and five horizontal" expressway network and an important transportation support project for the 2022 Asian Games. After completion, the project will interconnect with north-south express corridors such as Zhonghe Elevated Road, Qiushi Elevated Road, and Shanghai-Hangzhou-Ningbo Expressway, greatly improving Hangzhou's long-distance rapid accessibility.

Section 02, constructed by China Railway Tunnel Stock Co., Ltd., starts from the Xixi Campus of Zhejiang University in the west and ends west of Jianguo North Road in the east, with a total length of 3.26 kilometers. It includes a shield section of 1.77 kilometers, an open-cut north line of 1.32 kilometers and south line of 0.8 kilometers, the demolition and reconstruction of 3 mainline bridges, and the construction of 2 new bridges.

The "Chuxin" shield has a diameter of 13.46 meters, an overall length of about 169 meters, and a total weight of about 3,200 tons. It is suitable for universal segment rings with an outer diameter of 13 meters, an inner diameter of 11.9 meters, and a ring width of 2 meters. It was launched on October 27, 2020.

The Tianmushan Project is located in the Wulin Square commercial area, surrounded by dense buildings and numerous risk sources. The shield section uses two 13.46-meter-diameter slurry balance shields for construction. The transportation of super-large-diameter shield equipment, material supply, and settlement control are the top priorities of project construction.

During transportation, the "Chuxin" shield needed to pass through three administrative districts in Hangzhou—Xiaoshan District, Binjiang New District, and Xiacheng District. Half of the more than 20-kilometer route was in Hangzhou's main urban area. With strong support from the Hangzhou Municipal Construction Commission and local transportation departments, during the transportation planning stage, the Tianmushan Project conducted detailed surveys of every turn and every bridge along the transport route. The 360-ton cutterhead was divided into five pieces and transported separately, and the traffic police department provided full escort for the transportation of the 320-ton main drive.

The geological conditions of the Tianmushan Project are complex. The 680-meter fluid-plastic silty soil stratum and the composite stratum with soft upper and hard lower layers are the "natural enemies" of large-diameter slurry shields. At the same time, there are also risks such as heavy ground traffic, dense buildings and structures along the surrounding line, close lateral crossing of operating subway lines, and underground pipelines. To effectively control settlement, the project held multiple scheme seminars, refined the control of tunneling parameters during the process, and innovatively adopted simultaneous dual-liquid grouting to control settlement. By optimizing the large shield tunnel alignment to avoid moderately weathered tuff, continuous and rapid underpassing of subway lines during shield advancement was ensured. During project construction, a large number of outstanding Party members and advanced workers, such as Li Yachao, emerged.

As of late October, the south line of the shield section of Section 02 of the Huancheng North Road-Tianmushan Road (Zhonghe Interchange-Gucui Road) Upgrading and Reconstruction Project has been nearly 60% completed. Taking the "decisive battle in the fourth quarter" labor competition as an opportunity, the project will summarize the successful experience of the north line breakthrough, concentrate superior resources, complete the south line shield and open-cut section construction tasks with guaranteed quality and quantity, create a new calling card for the company's large shield construction, and help ensure the smooth holding of the Asian Games.