Date: 24^th Oct., 2018

Opening ceremony of Hong Kong-Zhuhai-Macao Bridge was held on the morning of 23^rd Oct., and General Secretary Xi Jinping attended the ceremony and declared the opening of the bridge. This large-scale sea-crossing transport engineering, the result of the fist cooperation of Guangdong, Hong Kong and Macao under the frame of “one country, two systems”, was officially put into use.

This is by now the longest sea-crossing bridge in the world and it is titled the “crown” in the history of world bridge construction. The most shinning part of the crown is the high technology of China Railway Hi-Tech Industry Co., Ltd. (CRHIC). In the construction process, CRHIC’s branch company China Railway Shanhaiguan Bridge Group was responsible for the fabrication of 180 thousand tons of steel structures for the largest Section CB01 of the bridge’s steel structure project, its branch company China Railway Baoji Bridge Group undertook the production of over 40 thousand tons of steel girders and steel towers, and its branch company China Railway Science & Industry Group researched and developed special transport equipment for removing, transshipment, and allocation and lading of steel box girders for Hong Kong-Zhuhai-Macao Bridge.

World’s First Time Larges-scale Use of Steel Box Girders 

Hong Kong-Zhuhai-Macao Bridge is another major infrastructure construction project following the Three Gorges Project and Qinghai-Tibet Railway, and it has been honored as one of “the seven wonders of the modern world” by UK’s Guardian newspaper. The complex structure of Hong Kong-Zhuhai-Macao Bridge has made it difficult to carry out the construction. If decomposing the structure of Hong Kong-Zhuhai-Macao Bridge, we could find that the bridge mainly consists of several large components including steel box girders (bridge deck), bridge piers and immersed pipes at the seafloor. The bridge engineering of Hong Kong-Zhuhai-Macao Bridge has employed steel amounting to 425 thousand tons, which is about 60 times the weight of Eiffel Tower, and it is the world’s first engineering involving such a huge-scale use of steel box girders.

On 16^th March, 2012, in the world-interested construction engineering bidding for Hong Kong-Zhuhai-Macao Bridge, China Railway Shanhaiguan Bridge Group successfully won the tender on fabrication of 180 thousand tons of steel structures used in the largest Section CB01 of the bridge’s steel structure project.

Bridge engineering and also the Hong Kong-Zhuhai-Macao Bridge’ main engineering was fully connected on 27th Sept., 2016

It’s hardly possible to finish the fabrication of huge amount of steel box girders by manpower alone, so the builders initiated a bold idea: use robot to do the welding and adopt assembly line work to produce the steel box girders, just as the factories’ manufacturing automobile parts. China Railway Shanhaiguan Bridge Group took the lead in studying automated fabrication and welding technology of plate element and developed a specialized technology of plate element fabrication featuring automation, informatization and intellectualization after hard works in development and product trials of automatic equipment, which is a totally different mode compared with the conventional production mode depending mainly on human power. This fabrication mode helped solve the problem of poor welding quality and stability in angle seam welding of U-shape ribs, improve the quality of steel box plate elements and extend the service life of the bridge.

“Workshop” and “assembly line work”, with which, the builders almost moved the whole “century engineering”- Hong Kong-Zhuhai-Macao Bridge into the factory, becoming a significant attempt in the history of super project construction.

'Tie' a 'Chinese Knot' Weighting 780 Tons

 Qingzhou Channel Bridge of Hong Kong-Zhuhai-Macao Bridge, constructed by China Railway Shanhaiguan Bridge Group, is a cable-stayed steel box girder bridge with double towers and double cable planes that has a biggest span of 458 meters and a main tower reaching 163 meters in height, standing as the navigation arch bridge that is the longest in span and the highest in main tower in the Hong Kong-Zhuhai-Macao Bridge. The two cable bent towers are H-type frame towers with Chinese Knot type girders.

“Chinese Knot”---Qingzhou Channel Bridge（made by China Railway Shanhaiguan Bridge Group）

The artistic “Chinese knot” set between the two cable bent towers shows a perfect combination of function and landscaping and bears the meaning of the “excellent match” between both sides of the strait and among the three places. It is the most remarkable and striking symbol of the Hong Kong-Zhuhai-Macao Bridge. According to information, this is the fist time to use steel“Chinese knot”as top girder both at home and abroad. The steel-knot brace has a total height of 50.30 meters and a total width of 28.09 meters, equaling to half of a football field; and its total weight is 780 tons with the maximum load of segments reaching 250 tons. As required by the design, knot brace’ installation height deviation should be within 2 millimeters and gradient tolerance be 1/4000, which are of high difficulty and high risk in regard to installation but claim no mistake in every factor. China Railway Shanhaiguan Bridge Group successfully completed this high-difficulty “dance in the air” and finally “attached” a beautiful “Chinese knot” to a place 160 meters high above the surface of Lingsing Sea.

“Sail-shape” Twin Towers Set the Sail of “Power”

China Railway Baoji Bridge Group has also played an important role in the construction of Hong Kong-Zhuhai-Macao Bridge. It undertook the fabrication of all steel structures used in Section CB05-G2 of the bridge, including Jiuzhou Channel Bridge, 4-continuous unit and 23-arch non-navigation arch bridge in shallow water, steel towers etc, with the total length of steel structures being 2, 648 meters and the total amount of them being over 40,000 tons. Among them, the two “sail-shape” steel towers, composed of vertical tower pillars and curved arms, were considered even more difficult. The designed height of each tower is 101 meters, about the height of a 30-floor building, and its weight is 2,300 tons.

According to information, steel tower is the main structure of the cable-stayed bridge to receive the load and its service life affects that of the bridge directly. In order to fabricate out the steel towers with 120 years’ service life and to reduce the wielding work load at sea, China Railway Baoji Bridge Group managed to install the steel tower by entire large segment hoisting after having finished the fabrication of the whole steel tower in the factory.

“Sail”--Jiuzhou Channel Bridge（made by China Railway Baoji Bridge Group）

During the construction period, after tackling with a great deal of problems regarding the technology, the enterprise developed the domestically first entire large segment fabrication technology of steel tower, and had the steel towers above the sea surface joined up into entire large segments in the factory. The entire large segments are totally 67.9 meters long, 4.12 meters wide, 18.35 meters high and about 1,000 tons heavy, fairly the “giants” among entire large segments of steel tower in China. In 2014, these two entire steel towers were transported to Zhuhai and were successfully hoisted into their locations in the bridge. The steel towers fabricated by China Railway Baoji Bridge Group passed the non-destructive testing made by the in-factory supervisor and the third party testing company, who were entrusted by the Hong Kong-Zhuhai-Macao Bridge Authority, with all steel towers reaching the technological standards set for Hong Kong-Zhuhai-Macao Bridge on a 100% basis. And this kind of steel tower is honored as “the new milestone in China’s processing and fabrication technology of bridge used steel tower”.

Now, looked from the North Qinglv Road of Zhuhai and by the coastline, the “twin sails” will come into your sight. The giant and tall towers sand on the sea surface, giving full play of the straight up power of Hong Kong-Zhuhai-Macao Bridge; the two towers ,resembling twin sails and with deep meaning, bear rich cultural connotation and beautiful wishes.

Portal Crane with a Capacity of 2000 Tons Assists in “Dolphin Turnover”

In the construction process of Hong Kong-Zhuhai-Macao Bridge, the concrete bridge pillar should be accurately jointed with the steel structure brace, which gives higher requirements to selection of hoisting equipment and lifting work on the sea. To this end, China Railway Science & Industry Group specifically researched and produced a steel-box-girder-used electro-hydraulic balanced module transporter with a capacity of 4,000 tons and a dual-track portal crane with a capacity of 2,000 tons for removing, transshipment, and allocation and lading of steel box girders.

Dual-track portal crane with a capacity of 2000 tons (researched and produced by China Railway Science & Industry Group)

It is learnt that, in Section CB02 of the bridge engineering which is also the main engineering of Hong Kong-Zhuhai-Macao Bridge, the bridge built at the channel for river-sea direct vessels is a steel box girder and cable-stayed bridge with central-parallels single cable plane and three towers. The cable bent tower is a “dolphin-shape” steel cable bent tower, and it is said that 138# steel cable bent tower needed to be changed to a secondary tower and its transport and hoisting works should take place on the lower part of the main tower because of limitation in the on-site hoisting conditions. This “dolphin-shape” steel cable bent tower is extremely large, heavy and in irregular steel structure, and its turnover is regarded as the first practice in home and hardly has precedents in the world. After on-site investigation, the construction unit decided to use the portal crane with a capacity of 2,000 tons produced by China Railway Science & Industry Group to implement the 180° turnover at the equipment base.

With no reference materials being available, turning-over load being as high as 3,234 tons and numerous unpredictable factors, structural calculations and plan-making were faced with huge difficulty, and whether this 180° turnover would be achieved or not directly affected the progress of the whole Hong Kong-Zhuhai-Macao Bridge engineering. Since Oct., 2015, China Railway Science & Industry Group had repeatedly made calculations and simulating practices, and worked out a safety assessment report by mechanical analysis. And finally, on 14^th May, 2016, the portal crane with a capacity of 2,000 tons produced by China Railway Science & Industry Group successfully turned over the “dolphin-shape” steel cable bent tower. This technology has achieved two national patents and is identified by Hubei Province Science and Technology Department as an international leading technology as a whole.

The participation in construction of Hong Kong-Zhuhai-Macao Bridge is not only a thorough practice of the “manufacturing power” strategy but also the actual practice of the important “three transformation” instruction put forward by General Secretary Xi. CRHIC’s contributions to the progress of China’s transportation technology will definitely go down in history together with Hong Kong-Zhuhai-Macao Bridge’s officially opening to the public, and the “Chinese knot” and “Sail” will become the most beautiful scenery on the Lingding Sea.