精选优质文档-倾情为你奉上Birds NestAbstract: The main venue for the Beijing Olympics, the National Stadium, widely known as the Birds Nest because of its unique design, has become a nationwide sensation. The removal of the elements helped to bring the project under the reduced construction budget of $290million, from an original $500million. With the removal of the retractable roof, the building was lightened, which helped it stand up to; however, the upper section of the roof was altered
