Reality and Prospects for China’s Undersea Tunnels

3 min read

After the completion of Xiangan Tunnel, many undersea tunnel constructions were successively carried out in China, including the completed Jiaozhou Bay Tunnel, and another two tunnels under feasibility study, Bohai Strait Tunnel and Qiongzhou Strait Tunnel.

Completed projects

Jiaozhou Bay Undersea Tunnel, also known as the Jiaozhou Bay Tunnel, is China’s longest undersea tunnel of 7,800 meters with 3,850 meters onshore and 3,9 50 meters offshore. The tunnelis located at the mouth of Jiaozhou Bay, connecting Qingdao and Huangdao with six bi-directional driveways.

The Jiaozhou Bay Tunnel construction in Qingdao started on December 27,2006 and officially opened to traffic on June 30,2011. After the opening, Qingdao citizens could reach Huangdao in only 6 minutes. This tunnel helped to realize the “urban integration”between the eastern and western coast of Qingdao, to end the era of people only relying on ferries to travel across Jiaozhou Bay, and to achieve a half hour economic circle between both sides.

Projects to be constructed

Xiamen Second West Passage Tunnel. After completing the east passage(Xiangan Tunnel), Xiamen is considering constructing the second west passage(Haicang Tunnel following the first west passage, Haicang Bridge). Currently, the project proposal has been submitted to National Development and Reform Commission (NDRC) for approval, and the start date of the main work is still unknown.

Xiazhang Tunnel. It would be the third undersea tunnel in Xiamen, connecting Xiamen Island and Zhangzhou Development Zone. After completion, it would take only 10 minutes to drive from Xiamen to Longhai of Zhangzhou, and the most direct beneficiary then would be Zhangzhou Campus of Xiamen University, as well as a series of large-scale real estate projects nearby. The first artificial ecological island “Double Fish Island”approved by the Chinese State Council could also get some profits from this.

Bohai Strait Tunnel. The scheme for this tunnel was finally determined at the end of 2013. This tunnel is designed to be 123 km connecting Dalian of Liaoning and Yantai of Shandong. This spanwould make it the world’s longest undersea tunnel, largely exceeding the Seikan Tunnel in Japan (about 54 km), and the Channel Tunnel(about 51 km). While the straight-line distance between Dalian and Yantai is only 170 km, it takes 6.5-8 hours to cross by ship. Worse than that is the fact that every year this area for one month this area is unnavigable due to storms. After this all-weather Bohai Strait Tunnel opens to traffic,2 hours will be the maximum time to cross. Insiders assume that if the daily traffic is 30,000 vehicles, and each one saves 500 km of journey, as much as one million tons of oil could be saved each year, equivalent to a whole year’s crude output of a medium-sized oil field.

Qiongzhou Strait Tunnel. The construction period of Qiongzhou Strait Tunnel is about eight years. It will be completed after 2020, with a total investment of over RMB 100 billion. Currently, relevant research reports have been finished. Once approved, Hainan’s economy will transfer from an”offshore economy”to a”peninsula economy”.

Currently, relevant experts believe that Qiongzhou Strait is more suited to having a tunnel rather than a bridge. Both technology and environmental factors show the infeasibilities of a bridge.

There are oil tankers crossing the strait every day, thus the bridge has to be over 70 meters high, which is not technically feasible. Even if the bridge is built in the narrowest part of the strait, it would be 18 km long. Considering the complicated geological conditions, it would be difficult for a bridge to resist super typhoons, super waves, earthquakes and other natural disasters.

However, the benefits of a tunnel are all obvious. In addition to all-weather operation, the environment, economy, military and security will all get benefits from it.