‘Where there’re roads, there’s prosperity’

An aerial view of the Shenzhen-Zhongshan Link. (PHOTO PROVIDED TO CHINA DAILY) 

Building the Shenzhen-Zhongshan Link is no less challenging, although the length of the super sea-crossing is less than half of that of the 55-kilometer Hong Kong-Zhuhai-Macao Bridge — the world’s longest bridge-cum-tunnel sea-crossing — says Chen Yue, one of the key engineers on the two mammoth transportation projects in the Guangdong-Hong Kong-Macao Greater Bay Area.

The tunnel construction pioneer has spent more than three decades in the industry since he helped build the Chinese mainland’s first immersed tube tunnel. Chen was appointed director of the office of the chief engineer at the HZMB Authority in 2008 and, upon the project’s completion, he became deputy chief engineer for the Shenzhen-Zhongshan Link.

“Although the HZMB links the two special administrative regions (Hong Kong and Macao) with other mainland cities, forming an outer ring within the Greater Bay Area, we still need a fully-developed inner ring transportation system among cities in Guangdong province, comparable to the well-established ring-shaped transportation networks of the San Francisco, New York and Tokyo bay areas,” says Chen.

Despite being about only 20 km apart as the crow flies, it currently takes at least one and a half hours for a one-way trip between Shenzhen and Zhongshan, which are located on opposite banks of the Pearl River. When the 24-km Shenzhen-Zhongshan Link comes into operation next year, there’ll be a direct cross-river link, slashing one-way travel time between the two cities to about 30 minutes.

Having grown up and worked in the Greater Bay Area for most of his life, Chen has witnessed the drastic changes that have taken place in the region’s transportation network. Prior to this interview with China Daily, he had gone on a business trip to Shenzhen.

Highlighting the significance of the “super project” (Shenzhen-Zhongshan Link), especially its economic benefits, Chen says Hong Kong’s influence on the mainland stands out among the cities along the eastern bank of the Pearl River, with Shenzhen at the forefront, while the development on the western bank has been comparatively slow.

“Where there are roads, there is prosperity,” says Chen, stressing that the link can contribute to the coordinated development of both sides.

Chen Yue, deputy chief engineer for the Shenzhen-Zhongshan Link, inspects a model of an engineering project. (PHOTO PROVIDED TO CHINA DAILY) 

Enhance technology prowess

He calls the colossal HZMB, connecting the Hong Kong and Macao SARs with the mainland, a “benchmark” and the “epitome of excellence” — it has offered invaluable insights for the construction of the Shenzhen-Zhongshan Link, while inspiring the teams involved to come up with even higher standards.

Unlike the HZMB’s six-lane dual carriageway, the Shenzhen-Zhongshan Link has an eight-lane dual carriageway, featuring a 46-meter-wide tunnel.

“Adding the two lanes has amplified the construction problems and costs as incremental changes have led to qualitative transformation,” explains Chen. But, these challenges can be addressed by upgrading equipment and training workers. This is also in line with the prevailing trend of enhancing quality and efficiency through equipment upgrades.

Citing the shift from traditional flame cutting to plasma cutting or laser cutting techniques for steel fabrication, he says this can lead to a reduction in material loss by two percentage points. It means that if a factory has an annual steel production of 200,000 tons, valued at 10,000 yuan ($1,368) per ton, any reduced material loss would help save 40 million yuan annually. Moreover, the advancement can also contribute to mitigating potential hazards to both the environment and human health.

By integrating bridges, artificial islands, an immersed tube tunnel and underwater interchanges, the Shenzhen-Zhongshan Link is an engineering marvel spanning seven shipping channels, including three major ones, in the Lingdingyang Area — a trumpet-shaped bay outside the Pearl River estuary. The western section is a bridge-based structure, stretching for a total distance of more than 17.2 km. Both Zhongshan Bridge and Lingdingyang Bridge cross one of the main shipping channels.

The eastern section deploys an innovative construction technique featuring a steel-shell concrete immersed tube tunnel, which passes beneath the third main shipping channel in the area. At both ends of the tunnel, artificial islands have been completed. The western artificial island takes on a diamond shape, resembling a “kite on the sea”, while the eastern artificial island covers an area equivalent to that of 48 standard football fields. The project is strategically located south of Shenzhen Bao’an International Airport, and will serve as a vital hub connecting the tunnel with multiple land highways.

Resilience against typhoons

Besides the costs and the diminishing availability of skilled workers, the impact of the natural environment on construction endeavors is a significant factor for Chen’s team to consider. The Shenzhen-Zhongshan Link is located in the open waters of the Pearl River estuary, which is prone to frequent strong typhoons during summer.

Ensuring the bridges’ ability to withstand high winds and avoiding construction delays caused by typhoons has been a prime concern for the project team.

Lingdingyang Bridge spans 1,666 meters, with a bridge deck height of 91 meters above the water, specifically designed to avoid disrupting the navigation of large vessels in shipping channels, while adopting higher requirements for its resilience against typhoons.

To deal with these problems, the project team collaborated with dozens of academic institutions and research organizations, including the wind tunnel laboratory at Southwest Jiaotong University, in conducting multiple rounds of tests and experiments.

According to Chen, they also cooperated with a meteorological forecasting center in the South China Sea region, which provides world-class weather predictions of up to 15 days in advance and seven-day forecasts tailored to the construction site’s location. This enables the prompt evacuation of personnel and equipment in accordance with emergency protocols before a typhoon strikes.

As next year’s scheduled opening of the Shenzhen-Zhongshan Link draws near, Chen admits his team has come under “mounting pressure”. But, the workers, who hail from different parts of the country, have not slackened in their efforts, even though the project is almost complete. This can be attributed to the comprehensive nature and strict standards upheld for major projects, which have had a gradual and far-reaching influence on all builders.

Chen is proud that many of the workers have been transferred to other projects, with their diligent and disciplined approach to work cultivated during their involvement in the two “super projects”. And, they’ve set an example and standards for other fellow workers.

In his private life, the seasoned engineer enjoys sports, and unwinds by playing badminton and soccer when he’s off work. Various facilities, including a basketball court, library and karaoke rooms, are provided for workers at sea to enrich their lives while they’re far away from land and their families.

Chen is eagerly looking forward to the grand opening of the Shenzhen-Zhongshan Link. But he also says, “Once it’s opened, there’ll certainly be a significant increase in traffic flow that could (place) considerable pressure on the operators.”