China-Singapore Jingwei, November 27th (Ma Jing intern Li Junhao) The World Cup is in full swing, upsets, goals, reversals... While the fierce competition has attracted attention, the topic of Chinese manufacturing not absent from the World Cup has also It's been fermenting.

Among them, the Lusail Stadium, which can accommodate more than 80,000 fans, has attracted much attention because of its high "medium content".

  This gymnasium, which resembles a "big golden bowl", "boarded" the 10-yuan Qatari riyal banknote, and also set the world's largest span double-layer intersecting cable-net roof single building and other six largest buildings in the world.

  Juli Rigging is also one of the Chinese companies participating in the construction. Sino-Singapore Jingwei recently had a conversation with Zhang Bei, the front-line leader of the project, to share how Chinese companies build Qatar's new "national business card".

Nearly 3,000 cables "support" the Lusail Stadium

  In this World Cup, Yiwu, the "World Supermarket", produced peripheral products such as jerseys, hats, and backpacks; Leo provided water supply equipment for Fan Village; Provided super-large display screens for the main stadium of the World Cup, and provided new energy bus connection services for King Long Automobile and Yutong Bus... Although the national football team is not here, Chinese manufacturing can be seen everywhere.

  Lusail Stadium, which undertakes multiple tasks such as semi-finals, finals and closing ceremonies, is also one of them. It has been praised by the local media as the "Pearl in the Crown" of the World Cup in Qatar.

Lusail Stadium was constructed by China Railway Construction International Group. It is the first time that a Chinese company participates in the construction of the World Cup main stadium as a general contractor of design and construction. The professional gymnasium with the most difficult production and construction.

No matter from construction equipment, manufacturing technology, design unit or professional construction enterprise, there are Chinese elements.

  The shape of Lusail Stadium is inspired by Arabian date palm bowls and enamel lanterns. From the outside, it looks like a "big golden bowl".

From the inside, the V-pillar of the steel structure is designed in a banana shape to avoid the collision between the column and the room. Each seat in the middle and lower stands has an independent air conditioner to ensure the comfort of watching the game.

  Juli Rigging is one of the participating parties of the Lusail Stadium project, and is responsible for the general contracting of the design, supply and installation of the entire roof cable-membrane structure system.

  Zhang Bei, Assistant President of Juli Rigging, has been stationed in Qatar for 5 years and participated in the project management throughout the process.

He told Sino-Singapore Jingwei that the project is a hyperboloid structure, using a complex double-layer crossed fish-belly cable-net structure, that is, the upper and lower layers, and the roof area reaches 67,000 square meters.

  "The cable is similar to a rope, with cast steel anchors at the two ends and a cable body in the middle. Then the cable passes through the ring beam steel structure and the cable clamp node to form the entire flexible cable network roof. There is no direct support under the roof of the entire gymnasium. The pillars are completely supported by the tension between each cable to support the entire long-span roof." Zhang Bei said.

  According to Zhang Bei, each of

the cables was manufactured in a Chinese factory, then shipped to the port for loading, and finally transferred to the project site in Qatar. Nearly 3,000 cables were used on the roof of the Lusail Stadium.

Millimeter-level precision requirements, 80% of the time is spent in high-altitude construction

  However, the ingenious and novel structural form and super-large span also brought great construction difficulties.

  Zhang Bei told Sino-Singapore Jingwei that in terms of span, the cable net spans nearly 300 meters, which is the fish-belly cable net single structure with the largest span and the largest cantilever distance in the world.

Not only that, the fish-belly structure also faces many construction problems. Before the radial cable truss is fully stressed, the structural stability is particularly poor, which is likely to cause structural instability and damage during lifting and tensioning, and even cause construction safety accidents.

"Under this structural form, moving any cable will change the entire roof cable network, which can be described as 'one hair moves the whole body'. The accuracy of the cables determines the final shaping effect of the entire roof and the final force of the entire cable network. state, so the requirements for the production and tensioning precision of the cable are particularly high."

Zhang Bei said.

  Zhang Bei also mentioned that because the cable is firstly assembled from the ring cable support frame more than ten meters high, the upper layer of the cable net is gradually assembled, and then raised to a certain height to assemble the middle strut in the air, and then the lower layer of the cable net is assembled, and then the overall Tensioning, workers spend about 80% of their time working at heights.

Moreover, the local climate is hot, and the temperature in summer can even reach 50 degrees Celsius, and the surface temperature of steel components can even reach 80 or 90 degrees Celsius. The construction must not only endure the high temperature environment, but also bear the risk of working at heights.

"The project adopts the European standard and the American standard as the calculation and acceptance standards. The installation error of the cable clamp, the adjustment deviation of the ring cable and the radial cable adjustment end, and the structural forming deviation are also controlled and accepted at the millimeter level."

Zhang Bei said, In addition, the project also needs to meet the local regulations of FIFA and Qatar. These triple standards also make the project very difficult, requiring a lot of analysis, simulation and calculation during the construction process.

  In the end, the project department repeatedly calculated the risk points in the construction process through the construction simulation analysis of the scheme, manual calculation and software application calculation, and discussed with the European consulting company, and finally successfully completed the overall improvement of the main cable network structure. Once it was pulled into place, all testing requirements met or exceeded the standard requirements, and no safety problems occurred.

The secondary cable system is tensioned in stages on the basis of the length accuracy of the cable product reaching 1 mm, which ensures the installation accuracy and drainage of the membrane structure in the later stage.

  It is worth mentioning that Zhang Bei said in his introduction that

domestic materials were used to replace European materials in the production of the cables in this project, and various technical indicators of the cables have reached the same technical level in Europe.

The bearing capacity of the cable breaks through the requirements of the Chinese standard, and the bearing capacity is increased from 95% of the Chinese standard to 100%. The length accuracy of the cable fully meets the project requirements, reaching the millimeter-level accuracy requirement, and ensuring the later construction requirements.

Steel castings are made in China with European materials. Since the materials have never been used in China, the product element ratio, heat treatment process, casting process and other links are strictly controlled. Through continuous adjustment and process optimization, various technical indicators of the product All meet the requirements of European standards.

It took five years, more than 1,800 days and nights, from the initial design to the production and supply of materials, to the calculation and analysis of the construction plan, approval, cable laying, lifting, and tensioning. On February 13, 2021, it was about 66 meters above the ground. The main cable net of the Lusail Stadium in Qatar with a total weight of about 2,300 tons was stretched at a height of 1.5 meters, marking the formation of the main structure of the building roof.

  Today, the Lusail Stadium with a total construction area of ​​190,000 square meters will hold a total of 10 games, including six group matches, a top 16 match, a quarter-final, a semi-final and the final. Fans will witness their stories with the World Cup here.

(Sino-Singapore Jingwei APP)