Yintai Center, which is located in the southwest of the intersection of Chang’an Avenue and East Third Ring Road in Beijing and north opposite to the International Trade Center, is now the landmark project in Beijing CBD. The Yintai Center comprises three super high-rise buildings, among which the middle one consists of hotel and apartments with a height of 249.5 meters and the other two with height of 186 meters serving as office buildings standing in the east and the west. Taking the middle one as an axis, the building group shows a symmetrical layout. Above the ground is a five-story podium building serving as a luxury brand retailer. The “Xiu” bar is located on the roof of the podium building surrounded by the three buildings, covering a building area of about 1,300 square meters.
How to unfold the bar’s different functional requirements and offer a flexible design in the intense axial symmetrical space among the tall buildings? Now that it was deemed as a desirable approach to represent the uniqueness of the bar in the form of traditional Chinese architecture amongst a highly modernized architectural complex, therefore the key to design, in my view, becomes the seeking of relationship possibility between the colossal modern complex and the moderately and cordially traditional ones.
I noticed that there was a strong spatial pattern of axis symmetry in traditional buildings, especially in Chinese imperial buildings. All the buildings with different scales and structures can be connected in series under the control of an axis, exhibiting a sequence space in gradual and cascading manner. This spatial relationship controlled by the axis is identical to the layout of the Yintai high-rise buildings, seemly showing the same logical relation. Thus, I took this intense axial relationship of the three high-rise buildings as the precondition and further extended it into the bar’s plan. Utilizing the centered north-south and east-west axes as a guide, the functions of the bar can be rearranged in light of the spatial contraposition and transformations, thus establishing a relationship between the surroundings and layout in terms of both plan and space.
For the purpose of coordinating traditional architectural form and functional requirements of the bar and avoiding the multi-walls and intense closure form in traditional northern buildings as well as highlighting such characters as openness and transparency of the bar, we undertook this special research and seriously took the advice of Mr. Fu Xinian, an expert on ancient architecture.
For the purpose of fire rating requirements, only steel supporting system can be applied in the buildings and fire prevention treatment of steel structure materials must be considered as well. Therefore, every piece of main rods and the relationship between rods at various locations must be strictly designed in accordance with Yingzao Fashi. Following the completion of site construction of steel roof truss, the beauty behind the steel framework of traditional buildings constructed by steel structures has already presented in front of us so vividly that it fills us with deep esteem notwithstanding the construction wastes everywhere on site and uncompleted main buildings of Yintai Center around. The sufficient knowledge of aesthetic values conveying in traditional buildings was achieved through the serious design relying on Yingzao Fashi.
After the completion of steel structure construction, the timber was applied for surface covering to show the texture of wooden architectures. In northern region, the timber is prone to temperature and humidity, thus easily being cracked, especially the elevation of building which is directly exposed to weather, causing unavoidable problem during construction. For the purpose of the said issue, we designed abundant technical nodes for comparison; in addition, we also made large models for further detailed research, and developed the final detailed design scheme. Indoor roof truss applied with rectangle section and all exposing wooden members and veneers were made from elm, disposed with reconditioning and applied with semi-gloss varnish top facing, the wood grain of which can be viewed. All wooden members and veneers underwent corrosion prevention, insect prevention, fire prevention and reconditioning treatment and complied with ancient architecture construction specifications. Since the partial wooden structures section was too small, it was completed by bolting with pure wooden components and steel flanges.