Recently, major construction projects such as the Chunfeng Tunnel, Mawan Cross-Sea Passage, Shenshan High-Speed Railway, and Shenzhen-Daya Bay Intercity Railway have made new progress. Among them, the construction of the Chunfeng Tunnel is nearing completion and is expected to meet traffic-opening conditions by the end of the year; the Mawan Passage, Shenzhen's first cross-sea passage, has achieved two-way breakthrough and is beginning to take shape; the Shenshan High-Speed Railway is expected to complete the erection of its first box girder in September this year.

The Chunfeng Tunnel is the largest-diameter shield tunnel under construction in South China, with a total length of 5,078 meters, including a shield tunnel section of 3,603 meters. It is being excavated using the "Chunfeng" extra-large-diameter slurry balance shield machine independently developed by China. The tunnel was successfully holed through on April 28 this year and has now entered the final stage.

It is understood that the Chunfeng Tunnel has a single-layer height of 4 meters and a width of 10 meters, which will be able to accommodate the passage of small and medium-sized vehicles while improving traffic efficiency. After the Chunfeng Tunnel opens to traffic, it will together with the existing Chunfeng Elevated Road form a composite east-west corridor in Shenzhen, and the traffic capacity of the Chunfeng Road section will be increased by about one fold.

While the land transport network becomes increasingly dense, Shenzhen's first "cross-sea tunnel" is also beginning to take shape. The Mawan Cross-Sea Passage is Shenzhen's first cross-sea passage and currently the largest-diameter subsea shield tunnel under construction in China. The route is about 8.1 kilometers long and is divided into two parts: an above-ground road and an underground road. It is understood that after the project is officially completed in 2024, the Qianhai area will be able to reach the Bao'an Central area quickly and directly, and at the same time the freight traffic pressure in the Nanshan Port area will be effectively reduced.

At present, Shenzhen has built a cumulative total of more than 1,300 kilometers of tunnels and has achieved a number of globally leading technical results in fields such as subsea tunnels, underground stations, and shield construction. The continuous breakthroughs and iterations in tunnel construction technology have greatly enhanced the speed and quality of urban construction.

In terms of high-speed railway construction, recently at the Ebu Girder Fabrication Yard of the SSSG-1 section of the Shenshan High-Speed Railway, as concrete slowly entered the box girder formwork from the pipe of the placing machine, the prefabrication of the first box girder for the entire Shenshan High-Speed Railway line was launched and completed successfully in 5 hours. The erection of the first box girder is expected to be completed in September this year.

The launch of the prefabrication of the first steel box girder marks the official start of box girder prefabrication construction in the Shenshan Special Cooperation Zone section of the Shenshan High-Speed Railway, and bridge construction is about to shift from the substructure to the superstructure.

The Shenshan High-Speed Railway has a total length of 125.5 kilometers, including about 52.5 kilometers in the Shenzhen urban section, about 56.1 kilometers in the Huizhou section, and about 16.9 kilometers in the Shenshan Special Cooperation Zone section. The entire line has 6 stations: Xili Station, Luohu North Station, Shenzhen Pingshan Station, Huizhou South Station, Huidong Station, and Shenshan Station. The maximum design speed is 350 kilometers per hour, and the bridge-tunnel ratio of the entire line is 92.6%. After the Shenshan High-Speed Railway is completed, it will take only 30 minutes from the Shenshan Special Cooperation Zone to the central area of Shenzhen, which is of great significance for accelerating the integrated development of the Shenshan Special Cooperation Zone with Shenzhen and its integration into the Guangdong-Hong Kong-Macao Greater Bay Area.

In terms of intercity railway construction, the Shenzhen-Daya Bay Intercity Railway, which spans four districts and directly reaches the airport, has also made new progress. Recently, the mode conversion, debugging, and acceptance of the dual-mode shield machine on the right line of the Huangmabu Station to Shiyan Center Station section of the Shenzhen-Daya Bay Intercity Railway were successfully passed, marking the successful completion of the shield machine's split-to-integral conversion and its first excavation mode conversion.

The Shenzhen-Daya Bay Intercity Railway (Shenzhen section) starts from T4 Station of Shenzhen Bao'an Airport, passes through Bao'an District, Longhua District, and Longgang District, and ends at Julong Station in Pingshan District. The line is about 69.2 kilometers long, with a design speed of 160 kilometers per hour. The entire line has 11 underground stations, namely T4 Hub, Airport East, Huangmabu, Shiyan Center, Longsheng, Minzhi North, Wuhe, Bainikeng, Universiade, Pingshan, and Julong.

It is expected that after completion in 2026, the fastest travel time from Pingshan to Shenzhen Airport will be only 40 minutes. By then, rapid connections between eastern, western, and central Shenzhen will be further strengthened. As an important channel for Shenzhen's external connections, the intercity railway is of important strategic significance for the interconnection of transportation in the Bay Area and the integration of the Shenzhen-Dongguan-Huizhou metropolitan area.