The scientific and technological force behind the structure of the "ice ribbon" oversized span cable net

Hangzhou, 20 Jan (Xinhua) -- The "Ice Ribbon" of the National Speed Skating Hall is surrounded by 22 crystalline ribbon-shaped curved glass curtain walls. The roof structure of "Ice Ribbon" is a super-large span cable network structure, with large span, large area and large space, and behind its construction and operation and maintenance guarantee, the Chinese team has contributed important scientific and technological strength.

"The so-called cable net structure, simply put, is a large net woven from steel cables. Such a large net 'buckled' above the National Speed Skating Hall, forming a saddle-shaped hyperboloid roof. Luo Yaozhi, a professor at the School of Civil Engineering and Architecture of Zhejiang University, introduced that the "ice ribbon" roof structure is woven from 49 pairs of load-bearing cables and 30 pairs of stable cables, with a long span of 198 meters and a short span of 124 meters, and the "ice ribbon" is also the world's largest span of single-layer two-way orthogonal saddle-shaped cable net roof gymnasium.

Since a rope net weighs several tons, it can only be woven into a net by reasonable tensioning. In the construction process of the cable net, the process of "first ground assembly, and then overall lifting" was adopted, due to the space limitation of the site, the steel cable laid on the ground waiting to be stretched needed to be slightly arched. Without accurate data support, no one can easily order the bending of a steel cable of several tons.

"The roof of the National Speed Skating Hall has a large span, many steel cables, and complex internal force coordination, which requires that the structure must be built with high precision." Deng Hua, a professor at the School of Civil Engineering and Architecture of Zhejiang University, introduced that the team created a miniature version of the "ice ribbon" model at Zhejiang University to simulate the whole process of the construction of the cable net structure and verify the design performance of the structure.

Based on a large number of numerical simulation results and test and test data, the Zhejiang University team put forward systematic plans and suggestions in the overall improvement of the cable net, tension control, construction acceptance and pre-tension monitoring, which provided strong technical support for the high-precision construction of the "ice ribbon" long-span cable net roof structure.

In addition, the team applied a load on the stretched cable net through sandbags, etc. "We hung different loads on the model to simulate the wind blowing snow and to verify the strength and deformation resistance of the roof." Deng Hua said.

In order to better understand the status of the steel cable and ensure the construction quality and safety, Luo Yaozhi's team installed wireless sensors independently developed by Zhejiang University in the construction process for real-time monitoring and mechanical analysis. Not only does it play a role in construction, but after it is completed, it still measures the "pulse" and "heartbeat" for the "ice ribbon".

"Getting the data, transmitting the data, and processing the data are the whole process of our monitoring and analysis." Xu Xian, a member of the Luo Yaozhi team of Zhejiang University and a professor at the School of Civil Engineering and Architecture, said that the team monitored the stress, displacement, acceleration, temperature, wind pressure and soli of the speed skating hall, and the number of test points was as many as more than a thousand.

Compared with the traditional rigid roof structure system, the flexible cable mesh roof greatly reduces the amount of steel used in the structure under the premise of meeting the structural function, so the exquisite space design provides a guarantee for energy saving and environmental protection.

"The technical level of modern spatial structure is an important symbol of a country's construction technology level. The constant quest for larger building spaces has led us to continue to research and innovate to meet the major needs of engineering construction. Academician Dong Shilin of the School of Civil Engineering and Architecture of Zhejiang University said. (End)