In early May, the section between Yunnan Road Station and Shanxi Road Station of Nanjing Metro Line 5 was successfully holed through, marking the completion of tunnel holing-through across the entire Nanjing Metro Line 5.

Nanjing Metro Line 5 has a total length of 37.4 kilometers. Along its route are both modern bustle and profound historical heritage, linking the "past and present" of the ancient capital of Jinling. Threading through the urban core of the ancient capital of Jinling and beneath its "millennia-old cultural lineage," the challenges of "what cannot be touched and what cannot be let go" are embodied most vividly in Nanjing Line 5.

The tunnel sections of Nanjing Metro Line 5 pass through numerous historical relics along the way, with as many as 25 cultural protection units at the ***, provincial, municipal and district levels involved above ground along the route. During shield tunneling, the project team carried out advance underground exploration of the sections to be crossed, adopted vibration-reduction measures in construction, and provided comprehensive, multi-level protection for the cultural relics along the line.

Line 5 is the line in Nanjing with the longest route, the most transfer stations, the greatest construction difficulty and the widest coverage area. During construction, there was no shortage of extreme crossings beneath numerous modern urban facilities. For example, in water-rich soft-soil strata, it successfully passed beneath the operating Metro Line 1 and Line 3 with "no perceptible impact"; achieved "zero" deformation in crossing beneath the pile groups of high-speed railway bridges such as the Beijing-Shanghai and Nanjing-Hangzhou lines, ensuring the safety of high-speed railway operations; precisely protected existing transport pipelines such as water supply, high-voltage utility tunnels, high-pressure gas pipelines, aviation fuel pipelines, and rainwater and sewage pipes; and navigated an extremely small R350-meter curve through various landforms such as floodplains and hillocks with "soft upper and hard lower" strata.

Line 5 crosses the three densely built urban districts of Nanjing's Gulou, Qinhuai and Jiangning, passing through several major commercial areas of Nanjing such as Hunan Road, Wutaishan, Fuzimiao and Dajiaochang, with numerous people and heavy traffic in the areas along the route. Faced with the question of how to carry out "undisturbed construction" in the urban core, the company's project team provided the "optimal solution" — realizing Nanjing's first 1.38m close-distance shield "stacked upper and lower" tunneling and receiving construction, solving the construction challenge of cramped sites in dense urban areas; and coordinating the entry and exit of 8 shields at the cramped Shanxi Road Station site, minimizing the impact on surrounding traffic.

In addition, Nanjing Metro Line 5 actively explores the application of new technologies, demonstrating the application of an intelligent digital shield autonomous cruising system in TA02 bid section, and achieving notable results in the exploration of digital intelligent construction.