Recently, the construction of hefei rail transit line 4 has made new progress. On December 24, the left line of fenglehe road station and yulan avenue station was connected, which became the 36th single-line tunnel of line 4. On December 30, the double-line shield tunneling machine from science avenue station to qimen road station passed through hewu railway and hefu high-speed railway.

Chunfeng tunnel project has been tunneling 128 meters, shield machine is under construction on the riverside avenue. Chunfeng tunnel excavation diameter of 15.8 meters. The chunfeng tunnel starts from binhe avenue in the west to the east side of the overpass, docking with binhe avenue in the east to the south side of xinxing interchange and docking with henan road, with a total length of about 5.08 km, including a tunnel length of about 4.82 km. Two - way four - lane, using a single - hole double - layer form, shield tunnel length of 3,603 meters. Chunfeng tunnel is the first municipal highway tunnel constructed by shield method in shenzhen. The tunnel is constructed by mud-water balanced shield tunneling machine with the largest diameter in China. The total length of the shield tunneling machine is 135 meters, the excavation diameter is 15.8 meters and the total weight is more than 4,800 tons.

On December 20, with the completion of the laying of the last pair of tracks on the left side of the water park station to nuo wo mulle station, the first phase of the Hohhot urban mass transit line 2 project under the general contract of China railway construction group and the construction of China railway 16th bureau group was completed.

On December 17, the world's largest underwater shield tunnel was successfully completed, marking significant progress in the construction of inter-city railway in the pearl river delta and adding new impetus to the construction of the guangdong-hong kong-macao greater bay area.

At the construction site of pazhou west section of guangzhou metro line 18, the cutter began to dig slowly, marking the first time that the fastest subway tunnel in China will cross the pearl river for a long distance. This shield tunneling machine will propel more than 1600 meters under the pearl river in an s-shaped manner, which will be the first time to challenge the long distance and small radius crossing the pearl river system in the field of underwater tunnel construction in China.

On December 15, an event was held in Shanghai to launch the project from taicang to the fourth tuantuan section of the shanghai-nantong railway and promote the integrated development of the Yangtze river delta.