The bridge is a core landmark building facing the Guangdong-Hong Kong-Macao Greater Bay Area in Guangzhou. On the morning of February 3, 2021, the Mingzhu Bay Bridge in Nansha New Area, Guangdong Free Trade Zone, China closed, marking the world’s largest span of three main truss steel truss arch bridges was refreshed to 436 meters , Surpassing Nanjing Dashengguan Yangtze River Bridge and aspiring to become the "world's first span".

In the future, the Pearl Bay Bridge will form a high-speed transportation corridor between the main urban areas of Guangzhou, Hong Kong International Airport, Shenzhen Bao'an International Airport, and Guangzhou South Railway Station, achieving direct access to major urban centers in the Greater Bay Area in 30 minutes.

A bridge is like a flying rainbow, and cities are connected in the Bay Area

As one of China's most open and economically dynamic regions, promoting the construction of the Guangdong-Hong Kong-Macao Greater Bay Area is a major national strategy.

Guangzhou Nansha is located at the estuary of the Pearl River and the geographic and geometric center of the Guangdong-Hong Kong-Macao Greater Bay Area. Nansha District is a planned urban sub-center of Guangzhou and an important gateway for Guangzhou to the Guangdong-Hong Kong-Macao Greater Bay Area. In its 803 square kilometers, the Shawan Waterway , Hongqi Lishui Road, Shiziyang, Humen Waterway, Lingdingyang, one third is covered by water.

One bridge over the two sides, a new city

In March 2018, the Guangzhou Nansha Pearl Bay Bridge, which was awarded the EPC design and construction contract by the China Railway Construction Bridge Bureau, officially started construction. The Mingzhu Bay Bridge, located in the core area of the "Five Waters" confluence in the Nansha Mingzhu Bay Comprehensive Service Area, will be crossed. Crossing the 1300-meter Longxue South Waterway across the Pearl River Estuary, it becomes an important traffic channel connecting Nansha Street and Wanqingsha in Nansha District.

A world-class bay area, to build a world-class bridge

The total length of the Pearl Bay Bridge is 9.1 kilometers, and the main bridge is 2.64 kilometers long. It is a half-through six-span continuous steel truss arch bridge. It adopts a three-piece truss structure. The total weight of steel beams is 54,000 tons. The appearance of the steel truss arch bridge echoes well. Here, the Wushuihuiwan, the natural and geographical environment that is connected by mountains and rivers, the bridge integrates "appearance" and "connotation", which is a super municipal bridge project.

Bridge construction must pass "five passes"

The first is the "technical barrier". The three main truss steel truss arches are erected with double cantilever, which undergoes multiple system transformations in the process.

The second is the "geological pass". There are multiple fault zones in the bridge site area and the geological conditions are complex.

The third is "Deep Water Pass", the maximum water depth at the bridge is about 30 meters.

The fourth is the "safety check", which is greatly affected by typhoons, with an average of 2 to 3 typhoons per year.

The fifth is the "Environmental Protection Pass". The oceanic climate at the bridge location is remarkable and the environmental protection standards are high.

Passing through the barriers is difficult. In the nearly 3 years of construction, the bridge builders have applied for more than 30 national patents, 3 foreign patents, and more than 20 invention patents and scientific research results, many key technologies through scientific and technological research. Reach the world's leading level.

Technology steel bridge from Pearl River to Changhong

The first major problem facing the construction of the bridge is the construction of the main pier steel cofferdam. The total weight is nearly 2,000 tons. The double-walled steel box cofferdam with the size of 3 basketball courts and a height of 5 stories needs to be launched, floated, and positioned by the airbag method.

There are 1500 horsepower tugs towing in the front, 36 airbags with a length of 12 meters and a diameter of 2 meters are laid underneath, and large excavators are used to assist the traction on both sides. During the entire launching and floating process, there is a sense of sight of the aircraft carrier launching.

Super shocking, "building blocks" on the water surface of 1300 meters wide

The erection of steel beams is a very critical link in starting the construction of the superstructure. The main bridge has 83 sections. Since the Pearl Bay Bridge is a double-deck bridge, each section is composed of 6 steel beams on the upper and lower decks. The largest steel beam is 14 meters long and weighs 67.1 tons. . In the erection process, the lower steel beams must be erected first, and then the upper steel beams must be erected. The whole process is like "building blocks", which need to be gradually spliced from bottom to top and from outside to inside.

In order to overcome the difficulty of controlling the internal force and deformation of steel beams during erection, the builders designed a 100-meter sling tower with a unit weight of 1,600 tons, setting the current record for the tallest temporary steel tower and the largest weight.

Refining "Ding Fengzhu", academician "think tank" will help

The Pearl Bay Bridge is located at the estuary of the Pearl River. Typhoon factors have a huge impact on the construction of the project. Typhoons generally occur from June to October, with an average annual impact of 2.85 times, and the maximum wind force is above 15 levels. During the construction period, the erection of the main bridge steel beams experienced two typhoon periods.

In order to ensure the reliability of the steel beam erection of the main bridge, especially the assembly of the buckle tower during typhoon periods, the technical team of the Pearl Bay Bridge repeatedly studied and demonstrated the reliability of the 100-meter buckle tower, and continuously optimized the structure type and section size of the buckle tower. The strength, stiffness and stability of the buckle tower were calculated, and the "wind tunnel gas bomb test" was conducted in conjunction with Hunan University.

The experimental results show that the strength and stiffness of the bridge structure under the design wind load during the construction phase meet the requirements of the code. The buckling tower of the bridge has successfully withstood the test of Typhoon "Hygos".

The Pearl Bay Bridge is scheduled to open to traffic on July 1, 2021. After the main bridge is closed, it will enter the bridge deck construction stage such as the installation of bridge slabs. It will connect the two sides of the city and watch the Pearl River estuary to help Guangzhou Nansha draw a picture. A beautiful and harmonious picture of bridges, mountains, forests, cities and seas. Editor/Sang Xiaomei