The maximum rotation angle of the bridge is 88 degrees.
This load test fully inspected the construction quality and structural stress performance of the bridge, determined the actual operation status and service conditions of the bridge, and provided a scientific basis for completion acceptance and operation.
21500 tons! The cluster swivel “record setting” construction area crosses three busy railway lines, Weijing on-line and caige off-line.
Three surveyors are arranged for each bridge during the rotation, Monitor the position of the beam end.
The whole process takes 82 minutes to complete the rotation of 0.1mm within 90 minutes! The key to the success of intelligent construction of “more efficient” bridge rotation lies in the ball joint system, rotating support system, rotating traction system For the control of a parameter of the bridge balance system in the construction process, even if there is a millimeter error, the risk probability index will rise.
On average, a train passes every 3 minutes during peak hours.
Why do you need to rotate? As a key livelihood project in Chongqing, the second horizontal line project of expressway needs to cross 10 railway lines, of which five bridges need to cross three busy railway lines: Weijing on-line, off-line and caige connecting line.
In the use of ball joints, the unbalanced weight of beam body and the friction coefficient of ball joints are calculated by monitoring the instantaneous change of section steel stress when the temporary consolidation is relieved, so as to provide a powerful reference for the formal rotation weight and traction.
Five 21500 ton bridges were rotated in the air to achieve accurate docking.
It is the first “five bridges in the world” When the project is about to open to traffic, let’s review the feat of this great project 👇 At 1:55 a.m.
In order to prevent mutual interference between bridges, the four counterclockwise rotating bridges rotate for 15 degrees at a rotation speed of 1.15 degrees per minute, and then the five bridges rotate simultaneously at a rotation speed of 1.72 degrees per minute.
It refreshes “the number of large-span cluster swivel bridges is up to more than 3, and the large-span cluster swivel tonnage is the heaviest, and the multi-t-structure swivel bridge is connected for the first time” World record 82 minutes! Four Inverses and one sequence “zero interference” in order to minimize the synchronous rotation interference of five bridges, “four Inverses and one sequence” is adopted The unique rotation method is that four bridges rotate counterclockwise and one bridge beam rotates clockwise.
When the railway operates at high speed, all construction along the line must be stopped.
When the remaining arc length at the beam end is 3M, enter the rotation deceleration stage.
In order to ensure the normal operation of the railway, after a lot of analysis and research, the contractor Zhongjian tunnel communicated with the design and railway parties for many times, and finally boldly and innovatively proposed the “synchronous Swivel Construction” scheme for five bridges, that is, the bridge construction scheme of “ectopic pouring first and then synchronous swivel”.
The precision instrument with an error of 0.1mm is used for real-time monitoring to ensure that the installation accuracy of the ball joint is controlled at 0.5mm and the accuracy of the center of the rotating shaft is controlled at 1mm Meet the ultra-high precision of bridge rotation and improve the installation speed â–² weigh and balance the weight before rotation to ensure that the stress at both ends of T structure is balanced.
During construction, the shortest distance between the swivel bridge and the outside of the railway line is only 2.9 meters, and the beam bottom is only 0.5 meters from the top of the railway catenary â–² in order to ensure the normal operation of the railway, the project adopts “ectopic pouring first and then synchronous swivel” The scheme crosses three operating railway lines at one time â–² after the rotation, five long-span bridges with a total length of 383.5 meters are synchronously rotated at one time in the same area and plane, with a total weight of 21500 tons, equivalent to the weight of 15000 cars.
The fusion satellite signal and BIM system are also developed and used “Three lines and five bridges swivel detection platform” system is equipped with “Intelligent Parking Aid System” for swivel construction.
On average, a train passes every 3 minutes during the peak period.
That is, the project will first build five bridges of the expressway, and then rotate and connect synchronously in the 90 minute railway night “skylight period”.
Architectural media ID: jianzhong001 remember the world’s first “five bridges turn at the same time” on major media platforms in August last year? She’s opening to traffic! From September 20 to 23, the load test of Lijia Jialing River Bridge invested by China Construction Fifth Engineering Bureau and constructed by China construction tunnel was successfully completed.
It was constructed for 2 years, planned for 2 months, arranged for 2-week trial operation and commissioning for 2 days, and officially rotated for 82 minutes.
In order to ensure the smooth completion of the rotation of the five bridges in the same rotation, a large amount of data calculation and repeated simulation are carried out before the rotation.
It shows the panoramic image of five bridges turning at the same time, eliminates the blind angle of swivel, and gives praise to Chinese project builders! (source: integrated on the network, the picture and copyright belong to the original author, please contact and delete if there is infringement!) long press the QR code to follow us  ▶▶▶。.
When the remaining arc length at the beam end is about 1m (1.6 degrees), jog and accurately put it in place.
on August 21, 2020, the second horizontal line project of Chongqing Expressway crossed the “three lines and five bridges” of the main bridge of Weijing and caige railway, successfully rotated and set a number of world records.
