Liu Hui, a reporter from the Oriental Network, reported on January 27 that as the opening of the Winter Olympics is getting closer and closer, the National Bobsleigh Center has once again sounded the charge horn and entered a state of preparation for "war".
One of the most difficult new venues for the Winter Olympics
The National Bobsleigh Center Circuit "Snow Dragon" is the first bobsleigh track in China, the third in Asia and the 17th in the world to meet the Olympic standards. Surrounded by mountains and forests, the design of the venue with Chinese temperament is like a dragon soaring on the ridge, looming and swimming among the mountains and forests.
The total length of the track is 1975 meters, with 16 corners, the maximum design speed is 134.4 kilometers per hour, the vertical drop is more than 121 meters, it has a world-unique 360° swing, and there are 3 track departure areas with a total audience seat of 7500 seats.
The National Bobsleigh Center, built by Shanghai Baoye, will undertake all the competition contents of the three Olympic sports of bobsleigh, steel frame bobsleigh and bobsleigh, so that the audience can feel the charm of bobsleigh and bobsleigh sports.
Because of the high professionalism of the project and the strict site requirements, the National Bobsleigh Center is considered to be one of the new winter Olympic competition venues with the highest design difficulty, the greatest construction difficulty and the most complex construction process.
The project participated in the key special project of the 2018 National Key R&D Plan "Science and Technology Winter Olympics", formed 5 track technical standards and acceptance standards, fully met the international certification requirements of the track, and achieved a breakthrough of zero in China. The National Bobsleigh Center project is also a science and technology research and development project, and has applied for 131 patents (including 57 invention patents) so far, and has won a number of national, provincial and ministerial awards.
The ice-making team was born
Special construction needs have spawned new technologies and teams. In the process of construction, the National Bobsleigh Center has opened a number of domestic "firsts" and filled a number of domestic technical experience gaps. The flattening error of the surface of the special-shaped twisted track structure should be controlled within 1 mm, and the developers boldly innovated and used shotcrete for the main structure for the first time.
In order to build this 1975-meter-long concrete track with three-dimensional twisting and able to withstand more than 400 freeze-thaw cycles, the project team independently developed a new concrete material, independently trained the first concrete sprayer in China, and ensured the success of the one-time pouring of the track with millimeter-level precision.
The environment of Xiaohaituo Mountain is complex, the track is undulating, the high drop difference, and the situation of multiple curves add many difficulties to the control of ice temperature. After more than a thousand attempts, the ice-making team finally successfully concluded the relationship between the ice-making temperature and the outside temperature. For example, a temperature of -4 °C ~ -7 °C can produce the best speed and durability of ice; -3 °C ~ -5 °C can reduce the frost to a minimum, should not make the ice surface dent.
At the same time, the formation of the ice channel must maintain continuous water spraying operations, and the ice-making team continuously sprays hundreds of layers of extremely thin water mist with an attitude of excellence, so that the ice channel with a total area of 7000m and a thickness of 50mm is "natural". Once the bubbles move outward to form small dents, they will affect the athlete's gliding trajectory and even endanger life safety.
Structural error ice repair is the most test of the skills of ice repairers. The highest quality ice replenishment material is natural snow, which is crystal clear and blends perfectly with the ice surface. For the in and out of the bending trajectory, as well as the poor ice making effect caused by the ice shedding, the ice repairer mixed the snow and water thoroughly, filtered, and used a special ice repair tool to repair the ice.
【Source: Orient Network】