Entering the autumn of Shenzhen

tens of thousands of birds like seagulls and herons flying together

Shenzhen Bay, with clear water and green shores, has become a paradise for migratory birds again

Just not far from the park

on the east-west main road of Binhai Avenue

the comprehensive transformation of underground space is in progress

When it is completed and opened to traffic next year

a huge green space will be released

forming a 3D traffic system that allows driving underground and enjoying the seascape above ground

Recently

our reporter visits the Comprehensive Traffic Renovation Project 

of Binhai Avenue (Headquarters Base Section)

to explore the tunnel for the citizens

At the entrance and exit of the tunnel, the construction site is busy. Photo by Yan Wenting, Reporter of Shenzhen Evening News

Four levels of underground space realize the space integration of transportation functions.

The reporter drove out of the busy Binhai Avenue and arrived at the construction site of the project. Looking up, you will find the formed tunnel is spacious and bright, and the lighting system is basically installed, entering the debugging stage. It is really shocking to see the "underneath" Binhai Avenue for the first time.

According to the staff of Shenzhen Transportation Bureau, the renovation project of Binhai Avenue (Headquarters Base Section) starts from the Shahe East Road interchange in the west to the Guangzhou-Shenzhen Expressway in the east, across Nanshan and Futian districts. The current two-way 10-lane road will be expanded to a two-way 14-lane road. Among them, the mainline has eight lanes in both directions, with a designed speed of 80 kilometers per hour; the auxiliary lane has six lanes in both directions, with a designed speed of 40 kilometers per hour.

Route Map of Binhai Avenue Project

The center line of the renovated road runs along the existing road, with a total length of 5,950 meters, divided into an underground tunnel section and a renovated surface road section. Among them, the underground tunnel of the main line has a buried section of 1,057 meters and an open section of 503 meters; the renovated surface road section has a length of 4,390 meters.

The total length of the Binhai Avenue Tunnel is about 1,560 meters, and adopts the arrangement of paving, shallow burying, and in-situ sinking and layer stacking of main lines and auxiliary lines. In combination with underground development, the sunken tunnel section embraces integrated transportation facilities such as urban roads, underground bay bus stops, and intercity railway stations, creating four levels of underground space. Including: 

The first underground layer is the development layer of the upper cavity of the tunnel and the connection with the Super Headquarters underground space;

The second underground layer includes the north-side main and auxiliary roads, south-side main roads, and north-side underground harbor-style bus stops;

The third underground layer consists of the south-side auxiliary road, the south-side harbor-style bus stop, and the station hall of the Guangzhou-Dongguan-Shenzhen Intercity Line;

The fourth underground layer is the platform level of the Guangzhou-Dongguan-Shenzhen Intercity Line station.

The north and south auxiliary roads of the sunken tunnel section, separately located in the second and third layers, are connected to the Super Headquarters underground space loop at Second Shenwan Branch Street and Second Shenwan Road with two pairs of entrances and exits.

Rendering of the sunken section

Introducing scenic views into the city smart tunnel adopts multiple new technologies

Feng Jin, the person in charge of China Railway No. 4 Engineering Group's Binhai Avenue project, took the reporter into the interior of the tunnel, where new technologies and demonstrations could be seen everywhere. The reporter saw that the interior walls of the tunnel were all decorated with white enamel steel plates, and the most eye-catching feature was the transition zone at the junction of the tunnel and the ground, where a clever "light transition" was designed.

The builders closely coordinated the design of the dark excavation section with regional planning. Steel structure frames were used at the tunnel entrances and exits, with small densely spaced steel structures embedded in the top and sound-absorbing panels installed, while the rest was left hollowed out. When natural light shines into the tunnel, it creates a flickering effect, realizing the spatial effect of "introducing scenic views into the city". Feng Jin told the reporter that this innovative design not only enhances the visual appearance but also helps the driver better adapt to changes in light and darkness, thus improving driving safety.

As we went deeper, the reporter saw communication equipment resembling a mini base station installed at intervals on the top of the tunnel. According to Feng Jin, this is the latest pilot project of the underground transformation of Binhai Avenue. It adopts the latest Huawei Hongmeng Integrated Device and will achieve real-time holographic images inside the tunnel in the future, accurately mastering the driving trajectory of vehicles passing through the tunnel.

Workers are working on the transition zone between the tunnel and the ground. Photo by Yan Wenting, Reporter of Shenzhen Evening News

The sunken transformation of Binhai Avenue is facing many problems. The first challenge is the complex geological conditions brought by the coastal features. "19 years ago, this area of Binhai Avenue was all reclaimed land, with mudflats and sludge below, and the bottom layer is granite hard rock. Such chaotic geological conditions have brought new challenges for construction."

Binhai Avenue spans two districts, with a very large excavation area of 100,000 square meters, equivalent to the excavation area of 25 standard subway stations. Feng Jin told the reporter that the standard width inside the tunnel is 73 meters, while reaching 100 meters at the widest point, due to the realization of the first underground harbor-style bus station in the province, and also the inclusion of the station hall layer of the intercity railway.

To ensure the safety of the construction, the project has introduced new technologies: the use of beam string structure instead of temporary support of reinforced concrete, the use of squeezed branch pile instead of the traditional floating pile, and the application of double-curved surface lapped retaining wall. At the same time, based on the project's characteristics and requirements, a project-level digital control platform has been independently developed to achieve digital control of the project through progress (layered coloring of progress), safety (safety, monitoring, tower crane monitoring, personnel positioning, high-formwork monitoring, etc.), and quality (first-piece project, sample project, automatic spray curing).

The first case of urban underground space development in China

With the comprehensive transformation of Binhai Avenue in full swing, the good news came from the online award ceremony of the International Tunnelling & Underground Space Association (ITA) in 2023. After fierce competition, the Shenzhen Binhai Avenue Underground Transformation Project won "Project of the Year" at the 9th Edition of the ITA Tunnelling Award

Rendering of Light Transition

ITA Award

ITA Award is a prestigious global honor for international tunnel and underground space engineering, known as the "Oscar Award" of the tunnel industry. Model projects and exceptional engineers who contribute innovations and breakthroughs to global tunnel projects will be recognized by ITA every year. The ITA Awards for this year have seven categories. China won a total of 3 awards, making it the most awarded country of this edition.

The sunken transformation of Binhai Avenue combined with the development of the Shenzhen Bay Super Headquarters Base. The sunken tunnel section of the project has set up "two in and two out" dedicated ramps, forming a three-level underground road system of "underground expressway + underground ring road + underground parking lot" for the underground road network system of the Shenzhen Bay Super Headquarters Base, ensuring the large-scale transportation demand of the headquarters base and creating an efficient underground transportation system.

The sheltered corridor

At the same time, an intercity station for the Guangzhou-Dongguan-Shenzhen Intercity Rail, as well as the first underground bay-style bus station in China, has been set up under the tunnel. By utilizing overburden, the underground space is seamlessly connected with the underground space of the Super Headquarters Base. The project has become a super complex integrating road transportation, rail transportation, and comprehensive development, setting a new benchmark for intensive land use in the core urban area and promoting the comprehensive project of the Binhai Avenue transportation (headquarters base section) towards a model of "integrated transportation, unified functions, and allied urban underground space development".

According to the staff of Shenzhen Transportation Bureau, as of now, the overall progress of the Binhai Avenue Underground project has reached 91%, the excavation of the sunken section has been completed 100%, the main structure has been completed 98%, the road renovation section has been completed 95%, and the mechanical and electrical installation and decoration have been completed 50%.

Upon its completion, the Shenzhen Bay Super Headquarters base section will create a "ground + underground" integrated transportation system. It will successfully relieve Binhai Avenue's traffic bottleneck and relocate the block between Binhai Avenue and the Shenzhen Bay scenery to encourage the fusion of urban architecture and coastal nature, provide better public space, and establish a new source of energy for the Bay Area.