On January 13, the Daxiangshan Tunnel on the Fuzhou Binhai Express Line—China's first large-diameter single-shield TBM urban rail mountain tunnel—was successfully holed through. The Fuzhou Binhai Express Line connects Fuzhou Railway Station to Changle International Airport, with a total length of 62.4 kilometers and a design speed of 140 kilometers per hour. It is the fastest intercity railway from Fuzhou to Changle Airport, nearly twice as fast as a conventional urban subway. The Daxiangshan Tunnel on the Fuzhou Binhai Express Line is located in the Xiangqian Station–Shouzhan Station section, with a total length of 4.53 kilometers, all in ultra-hard rock strata of 120–220 MPa, six times the hardness of ordinary concrete. It is characterized by rapid shield cutter wear and a high risk of shield jamming, and is currently the longest and hardest mountain tunnel in Fuzhou's rail transit system. In response to these working conditions, a specially customized 8.6-meter large-diameter single-shield TBM (full-face hard rock tunnel boring machine) was used for construction in this section.

Since the TBM launch on the right line of the Daxiangshan Tunnel in November 2020, the builders fought day and night for 13 months, replacing more than a thousand cutters, successfully crossing 3 geological fault zones and 8 densely jointed areas, and overcoming difficulties such as high water pressure and long-distance ultra-hard rock tunneling. They finally "cracked" the hardest nut in Fuzhou's rail transit construction, setting new Fuzhou rail transit construction records of 23.4 meters of TBM tunneling in a single day and 454 meters in a single month. In addition, the successful holing-through of the single line of the Daxiangshan Tunnel marks a major breakthrough for Fuzhou Metro in technologies such as in-tunnel TBM launch, portal sealing, and segment waterproofing and drainage. Once the Binhai Express Line is completed and put into operation, it will enable travel from the city center to the Binhai New City within 30 minutes and from Fuzhou Railway Station to the airport in 40 minutes, strongly promoting the coordinated development of northeastern Fujian and the central urban area of Fuzhou.