Schematic of the Jiangpu Road Tunnel's twin-tube, four-lane configuration

Rendering of the Yindu Road river crossing tunnel

At present, 16 highway tunnels have been completed beneath the Huangpu River. Major transportation arteries continue to extend under the Huangpu River. So how many Huangpu River highway tunnels are currently under construction? It is reported that three Huangpu River highway tunnels are under construction: the Jiangpu Road Tunnel, the Longshui South Road Tunnel, and the Yindu Road Tunnel. Among them, the Jiangpu Road Tunnel is scheduled to be completed within this year, while the Longshui South Road and Yindu Road tunnels are planned for completion in 2024.

■ Jiangpu Road Tunnel

The only tunnel that overlaps with a rail transit line

The Jiangpu Road Tunnel has a total length of 2.28 kilometers. It starts in the north at the intersection of Jiangpu Road and Longjiang Road in Yangpu District, crosses beneath the Huangpu River southward, and reaches Minsheng Road and Shangcheng Road in Pudong New Area. The tunnel is divided into a river section and an onshore section, with twin tubes and four lanes, and a diameter of approximately 11 meters.

Coincidentally, the under-construction rail transit Line 18 tunnel also crosses the Huangpu River at Jiangpu Road, overlapping with the Jiangpu Road river crossing highway tunnel multiple times over a long distance, alternating above and below.

According to disclosures, among all the overlapping sections, the most complex and difficult is the section where the shield-driven section of the Jiangpu Road Tunnel overlaps with the running tunnel between Danyang Road Station and Changyi Road Station on Line 18. This is also the only tunnel on the Huangpu River where a highway tunnel and a rail transit tunnel are built together in an overlapping configuration, with a minimum vertical clearance of about 3.4 meters between the two.

After multiple scheme discussions and expert reviews, the construction plan of "upper first, lower later" and "larger first, smaller later" was ultimately determined. During construction through the overlapping section, manual and automated monitoring methods were used to conduct real-time monitoring of structural deformation in the shield-driven section of the Jiangpu Road Tunnel. Longitudinal ties were installed on the segment rings of the shield-driven section of the Jiangpu Road Tunnel to improve tunnel stiffness and deformation resistance. Data from third-party measurements showed that all indicators fully met the standards.

As the first project to start construction during the 13th Five-Year Plan period among Shanghai's major river crossing facilities in the northern area, the Jiangpu Road river crossing tunnel is scheduled to open to traffic within this year. By then, traffic pressure on the Yangpu Bridge and other crossings will be effectively diverted, and the overall traffic function of the area will be significantly improved.

■ Longshui South Road Tunnel

Travel time of only 10 minutes

The under-construction Longshui South Road river crossing tunnel is an important river crossing channel in the southern part of Shanghai's central urban area. It plays an important role in enhancing connections between both banks of the riverside area in the southern extension of the Huangpu River and in diverting near-river cross-river traffic from the Shangzhong Road Tunnel. Once completed, travel time from Xuhui to Pudong is expected to be shortened to 10 minutes.

The key service areas of the Longshui South Road river crossing tunnel are medium- and short-distance trips from southern Sanlin and the Qiantan area in Pudong to Shanghai South Railway Station, the Xuhui riverside, Changqiao, and other areas. Upon completion, it will enable direct connection between the core area of the Xuhui riverside and the Qiantan area in Pudong, optimize the layout of river crossing facilities in the southern section of the Huangpu River, balance traffic pressure, and enhance transportation convenience on both banks.

The main line of the Longshui South Road river crossing tunnel is designed for a speed of 40 kilometers per hour, with four lanes in both directions. It starts in the west at the intersection of Longshui South Road and Xitai North Road in Xuhui District, where a ramp is planned on the Puxi side at Planning Road 6, and then crosses the Huangpu River in two lines, south and north. The north line reaches the intersection of Haiyang West Road and Yaolong Road in Pudong New Area, with a total length of 2.03 kilometers. The south line reaches the intersection of Gaoqing West Road and Yaolong Road in Pudong New Area, with a total length of 2.65 kilometers.

The Puxi section along Longshui South Road is surrounded mostly by mature residential communities, and there are numerous utilities beneath the road. To minimize impact on the surrounding environment, the north and south main lines of the Puxi section adopt a co-linear layout in plan with a vertically stacked design. The route uses a single-tube, double-deck, extra-large-diameter shield tunnel to cross the Huangpu River, after which it splits into north and south lines in Pudong, using two large-diameter shield tunnels to cross Qiantan Avenue. The north line connects to Haiyang West Road, and the south line connects to Gaoqing West Road. The entire project is scheduled to be completed and opened to traffic in December 2024.

■ Yindu Road Tunnel

Will ease pressure on the Xinzhuang Interchange

The Yindu Road river crossing tunnel is located in the near-suburban area of southern Shanghai, running east-west, and is an important channel connecting Xuhui District, Minhang District, and Pudong New Area. Once this project is completed and put into use, it will help promote suburban urbanization and also ease traffic pressure on the Xinzhuang Interchange and the western and southern sections of S20.

The Yindu Road river crossing tunnel starts in the west at the intersection of Planning Jingdong Road and Yindu Road in Xuhui District, and ends in the east at the intersection of Pujin Road and Luheng Road in Minhang District, extending along Yindu Road, with a total length of about 3.8 kilometers.

According to disclosures, the construction of the working shafts for this project is highly difficult, and the risks of shield launch and reception are high. During shield tunneling, many points must be controlled, including overcoming the difficulties of long-distance tunneling, shallow cover construction, and large shield turning, as well as crossing the flood control wall, docks, the Huangpu River, and other key points. Comprehensive control must be exercised over shield attitude, equipment operation, and various other aspects. To ensure the project schedule, the builders carried out simultaneous construction of shield advancement and internal structures.

The total construction period of the Yindu Road river crossing tunnel is about 50 months, and it is expected to be completed and opened to traffic in 2024.