According to Hefei Rail Transit, on April 18, the left line of the section from the Airport Work Area Station to the Aviation Industrial Park Station on the Hefei Xinqiao Airport S1 Line—the longest shield tunneling section in Hefei Rail Transit's history—was successfully holed through, marking the fourth single-track shield-driven section to be completed on this line.

The "Ji-Hang" (Airport Work Area Station to Aviation Industrial Park Station) section is the longest shield tunneling section in the history of Hefei Rail Transit construction. Its left line has a total length of approximately 3,257 meters and required the assembly of 2,178 segment rings. Due to the considerable length, one intermediate ventilation shaft was built at the midpoint of the section, and a segmented excavation approach was adopted: two shield tunneling machines were launched respectively from the Airport Work Area Station and the Aviation Industrial Park Station at either end of the section, boring toward the ventilation shaft in the middle. During shield tunneling, the machines passed beneath multiple structures and buildings at Hefei Xinqiao Airport, the airport flight control zone, and several underground pipelines and other risk sources, making construction highly challenging.

To ensure the smooth holing-through of the section, Hefei Rail Transit led the participating construction units in conducting specialized scheme demonstration and assessment focused on each risk source. During excavation, the site strictly controlled tunneling parameters and grout quality, and, in light of actual conditions, adopted secondary and multiple grouting to control segment ring uplift, and used multiple water-stop ring bands to block seepage and reduce risks. On-site monitoring of the ground surface was strengthened, with automated monitoring technology applied to key locations, and tunneling parameters were optimized and adjusted in real time based on monitoring data, thereby achieving the smooth holing-through of the section.

Up to now, the main structures of six stations on the Hefei Xinqiao Airport S1 Line have been topped out, and four of the 18 single-track shield-driven sections have been holed through.