9月17日上午11時，隨著建筑工人在“鳥巢”的頂端取下了最后一塊鋼墊塊，歷時4天的國家體育場鋼結構卸載順利完成。“鳥巢”由被外力支撐的狀態變成完全靠自身結構支撐。這也標志著國家體育場終于由圖紙上的構想變為一個偉大的建筑物。國家體育場主體結構分成兩個部分，即混凝土框架結構和鋼結構，混凝土結構被鋼結構罩在里面。鋼結構由24桁架柱圍繞著體育場碗狀看臺區旋轉而成，整體外觀酷似“鳥巢”造型。

The photo taken on September 17 shows an overlook of the Bird's Nest. [Xinhua] The steel structure of the National Stadium the main venue for the 2008 Beijing Olympic Games stood on its own yesterday after the last jack pad was removed. "Today is the birthday for the 'Bird's Nest,'" said Hou Zhaoxin, a top expert on the construction of 2008 Olympic projects. "With all the supporting structures removed, the huge skeleton of the National Stadium is able to stand on its own. The 'Bird's Nest' is born!" Designed by Swiss architecture firm Herzog & de Meuron, global engineering consultant ARUP and China Architecture Design and Research Group, the National Stadium is located on the North Fourth Ring Road in Beijing. The main body of the stadium is composed of 24 columns of trusses, which surround the bowl-shaped stands in the stadium. The structural elements support each other and converge into a grid formation, just like a bird's nest with interlocking branches and twigs. Construction started in December 2003 and the concrete work of the main stand was completed on November 15 last year. On August 31, the steel skeleton was welded together. The removal of the bracketing structures started on Thursday and was divided into seven steps. "During the process, 156 jacks were placed in 78 spots, and removal was done simultaneously on three levels the outside circle, the middle circle and the inside circle," said Li Aiqing, chairman of National Stadium Company, owner of the project. According to Li, the steel skeleton weighs 42,000 tons and can now bear a load of 11,200 tons of the roof and hanging parts. He said the entire steel structure would be completed by the end of November and the project completed by the end of next year. With a seating capacity of 91,000, the National Stadium will host the opening and closing ceremonies, track and field competitions and football finals during the Games. (China Daily)

Vocabulary:

truss: 構架, 桁架, 鋼梁 bracketing structures: 支架,支撐結構 （英語點津陳蓓編輯）