Chongqing, the "bridge capital", has added a new landmark across the Yangtze River. After more than 1000 days and nights of hard work, organized and implemented by Chongqing Housing and Urban Rural Construction Commission, the Chongqing baijusi Yangtze River Bridge jointly invested and constructed by CCCC second navigation bureau and Chongqing Urban Investment Group will be officially opened to traffic at 0:00 on the 24th. The bridge has many highlights from design to construction: the water drop shaped bridge tower is the highest bridge tower in the central urban area of Chongqing, reflecting the "language" element of Chongqing. The total weight of the steel truss beam of the whole bridge is about 44300 tons, equivalent to the steel consumption of 6.3 Paris Eiffel towers.
Baijusi Yangtze River Bridge project is a control node project of Chongqing's "seven horizontal lines" crossing the Yangtze River. It starts from chenjiage interchange in Dadukou District of Chongqing in the West and ends at taiyanggang combined interchange of inner ring expressway in Banan District in the East. The whole line is about 3.7 kilometers long. After the completion of baijusi Yangtze River Bridge, it will connect the four districts of Chongqing Jiangjin, Jiulongpo, Dadukou and Banan, and become an important channel directly connecting the Longzhou Bay area of Banan, Chongqing and the Yangtze River culture and art Bay area. At that time, it will only take Chongqing citizens more than 10 minutes to drive from Dadukou to Banan spring. At the same time, the construction of the bridge is of great significance to strengthen the connection between the surrounding areas, drive the economic development along the line, effectively promote the construction of the Yangtze River culture and art Bay area, and effectively alleviate the congestion of the inner ring expressway.
According to Du Chunlin, chief designer of baijusi Yangtze River Bridge and Deputy Chief Engineer (chief engineer of bridge discipline) of Chongqing Design Group Municipal Institute, baijusi Yangtze River Bridge has a total length of 1384m and a main span of 660m. It is the world's largest known public rail dual-purpose steel truss cable-stayed bridge. The bridge is a "highway + rail" dual-purpose bridge. The upper layer is a two-way eight Lane urban expressway, and the lower layer is a reserved river crossing channel for Chongqing rail transit line 18. The main tower of the bridge is a spatial multi curved water drop concrete structure, 236 meters high, equivalent to 84 floors high. It is the highest bridge tower in the central urban area of Chongqing.
On the eve of opening to traffic, many citizens went to the bridge to feel the charm of baijusi bridge, and water drop shaped Bridge Tower Photos brushed the screen in the circle of friends. According to Du Chunlin, the water drop shaped bridge tower is a major design highlight of baijusi Yangtze River Bridge. What is the meaning of this design? Du Chunlin said that the mountain city of Chongqing is surrounded by two rivers. It is born, prospered and beautiful because of water. The most important Chongqing "language" element of baijusi Yangtze River Bridge is water. Generally, the pylons of cable-stayed bridges are triangular or portal shaped. However, when designing baijusi Yangtze River Bridge, the team fully integrated Chongqing water elements and designed the pylons of the bridge in the shape of water droplets. On the one hand, it met the structural stress function, on the other hand, it also demonstrated the Chongqing People's fighting spirit of "water drops wear through stone, perseverance and perseverance" and the beautiful vision of "uniting strength, enriching the people and prospering Chongqing".
Baijusi Yangtze River Bridge is a cable-stayed bridge for both road and rail. The upper deck is 38m wide, which is an 8-lane urban expressway, the lower deck is 18m wide, which is a two-way track, and the width difference between the upper and lower decks is about 20m. How to solve the cable force transmission of cable-stayed bridge with large cantilever structure, wind vehicle bridge coupling vibration, steel truss aerodynamic and buffeting performance, as well as the position and structural relationship between track line 18 and main bridge and approach bridge is a major difficulty in the design.
Therefore, the design team of Chongqing Design Group Municipal Institute Company proposed the inverted trapezoidal triangular truss main beam section, which skillfully solved the problem of large difference between the upper and lower deck widths, greatly saving investment; At the same time, it innovatively integrates the intelligent design concept to realize the "whole life" health monitoring of the bridge. The design of the bridge has been completed with high level, high quality and high efficiency, which has laid a solid technical foundation for the scheduled opening of the whole line.
The main tower of the bridge is a spatial multi curved water drop concrete structure, which is divided into 55 sections, composed of upper, middle and lower beams and two tower columns. The two bridge towers use 60000 cubic meters of concrete and consume about 20000 tons of steel, which is equivalent to the total steel consumption of two Chongqing Raffles crystal corridors. Using BIM Technology, high-volume pumping concrete construction technology of high tower, key technologies of super long interval mass concrete construction, etc., the project team has overcome the problems of reinforcement batching, linear control, formwork processing, high tower concrete pumping, crack prevention of mass concrete and so on. On October 23, 2020, the two main towers of the bridge were successfully capped.
The steel truss beam of baijusi Yangtze River Bridge is arranged in inverted trapezoid, which is divided into 93 sections. The standard section is 15m long and weighs about 500 tons. It is bolted by 16 members and 1.1 million sets of high-strength bolts; The total weight of the steel truss girder of the whole bridge is about 44300 tons, which is equivalent to the steel consumption of 6.3 Eiffel towers in Paris. The steel truss frame is set with two main towers as the fulcrum, and the double cantilever symmetrical assembly construction is carried out on both sides respectively. The assembly length is large and the structural anti overturning risk is high. The project team strictly controlled all processes, used the "seesaw" principle, and took weight pressing measures in the secondary side span and middle span, so that the steel truss beam could be successfully erected on the side pier and successfully completed the side span closure; Then, through the process control of closure adjustment, closure linear measurement and closure length correction, the mid span closure task with 0.1mm accuracy will be completed with high quality on September 1, 2021.
Along the route, the bridge needs to successively cross the old Chengdu Chongqing railway eggplant Creek Railway Station, CCCC wharf, Dadukou Binjiang Road and Babin road. The construction environment is complex, the requirements for safety protection are high, and the external coordination is difficult. Among them, the most difficult operation is the erection construction of steel truss beams across 7 railway tracks. During the cross rail construction of seizing the "skylight point" two hours in the morning, the project team developed a "self-propelled integrated protection platform" hanging under the steel truss beam. The platform can not only promote the construction of steel truss beam synchronously, but also prevent falling objects from high altitude, ensure the construction safety, and obtain the national patent authorization.
