At 11:18 on March 9, 2022, as the last piece of steel box girder was stably fixed on the sling by the cable crane, the Yu-Chu Expressway Lvzhijiang Bridge under construction by CRCC and MBEC closed.

set three world records

●The first single-tower and single-span steel box girder suspension bridge in the history of world highway construction

●Main span 780 meters

●Maximum inclination angle of tunnel anchor up to 54 degrees

The Green Juice River Bridge is a key control project of the Yuxi-Chuxiong Expressway. It is located at the junction of Yimen County and Shuangbai County and spans the Green Juice River. The total length of the bridge is 798 meters, the bridge deck is two-way four-lane, the design speed is 100 kilometers per hour, and both banks are directly connected to the tunnel. The steel girder of the bridge is divided into 61 sections. The total weight of the steel box girder is about 10,000 tons, which is equivalent to an Alfie Tower. The maximum single-section lifting weight exceeds 180 tons.

Steel beams have new laws

The height difference between the bridge deck and the assembly yard is 320 meters, which is about 100 stories high. Especially the No. 27 beam section of Chuxiong'an, the erection method is the sliding erection of the separated steel box girder into the hole, and the construction difficulty is rare in China. During the erection process, the project team strictly implemented the "one hoisting and one inspection" system, and the steel box girders were hoisted in grid-based monitoring to ensure the alignment and position of the steel box girders were accurate. In response to the problem of slipping and erecting in the hole, the builders innovatively adopted the method of longitudinal auxiliary traction and follow-up traction of the overhead crane based on the actual situation, and took various measures to ensure the safety and efficiency of the steel beam erection work.

Intelligent integration into bridge construction

Since entering the construction site in 2019, the project builders have actively practiced the construction concepts of safety, civilization, green and environmental protection, implemented scientific management models such as safety points supermarket, and built facilities such as "safety platform" and "VR safety experience room". It has overcome many problems such as steep terrain on both sides of the strait, inconvenient transportation, high risk of high-altitude operations, and multi-layer cross-operation. Especially in the face of the inclination angle of the bottom plate of the anchor and plug body of Yuxi'an Tunnel up to 54°, the amount of ballast removal is large, the difficulty is large, and the construction period is tight. In addition, the multi-layer main body cross construction is adopted. The system cooperates with the construction method to make the construction of a single Yuxi'an tunnel anchor excavation only 4.5 months, which creates favorable conditions for the smooth erection of the bridge steel girder and the realization of the closing goal. And formed the "large inclination angle tunnel anchor rapid slag removal construction" construction method and "a super-inclination angle tunnel anchor large-capacity rapid slag removal construction method" patents, such technical achievements will be applied to plateau railway construction.

Yuchu Expressway is a very important part of Guangkun Expressway and an important part of expressway network in Yunnan Province, with a total length of 190.597 kilometers. After the project is completed, it will end the history of no expressway in Shuangbai County, Chuxiong Prefecture, and realize the interconnection of surrounding counties and towns. The travel time on both sides of the bridge will be shortened from the original 1.5 hours to 2 minutes, which will greatly improve the backward situation of infrastructure in the counties and towns on both sides of the bridge. , promote the transportation and economic exchanges in the surrounding areas, improve the investment environment, open up a fast channel for people along the line to increase their income and become rich, and play an important role in promoting tourism development and economic construction in central Yunnan.Editor/Ma Xue