How was the world’s first space frame structural curtain wall realized?

Today to introduce you to the late architect Zaha Hadid designed the landmark of Macau – Morpheus Hotel, the hotel cost 1.1 billion U.S. dollars (equivalent to 6.5 billion yuan), with a free-form exoskeleton, it is presented once again surprised the world of the entire building, in the surrounding complex to stand out, the entire project is the most difficult and the most.The most difficult and visually impactful part of the project is undoubtedly its inwardly curved sky bridge. From a distance, the whole shape is almost twisted at an angle that violates the common sense of powerlessness, and the difficulty of realizing it can be seen.

1.Project Overview

The entire project is 154.8m high, with a total of 43 floors of curtain wall area of about 45,000 square meters, the entire shape of the gradual change of the aluminum plate covered by the force, the mesh skeleton in the outside, the glass curtain wall in the inside, the combination of the middle of the building body with smooth surface, the transition of the three irregular cavities.

The exoskeleton of space frame steel structure surrounds the concrete core and the whole form is very unique. Five different glass panels are used to enhance the visual effect and reduce the amount of structure needed inside the building.

The project’s design was inspired by traditional Chinese jade carvings with their smooth curves and wind-like forms, which also determined the difficulty of its construction. According to statistics, the project used about 28,000 tons of steel, the equivalent of four Eiffel Towers. At the same time, 48,000 square meters of glass is enough to frame 120,000 “Mona Lisa Smile”, 70,500 square meters of reinforced concrete stacked together, is more than about 28 Olympic standard swimming pool.

 

2.Curtain wall design features

(1) The gradient space frame skeleton of the project is located in the outermost layer of the building, while the glass curtain wall is within the mesh skeleton.

(2) The inter-storey and visible areas have adopted separate installation modes and are made into different unit panels. The interstorey panels are supported at four points with the structure, and the visible panels can be installed from the interior, snap into between two interstorey panels, and build on the interstorey panels of the next floor.

(3) The interstorey unit block at the steel structure’s bull’s leg is designed to be cut into half slabs, which are assembled, fixed, sealed and reliably waterproofed directly at the site.

(4) The small radius curved panels at the corners require strict control of the accuracy of the panels to ensure that no corrugation occurs, as well as the accuracy of the bending profiles and processing and assembly to ensure their performance.

(5) The center position, all of which are shaped unit panels , where there are many twisted unit panels, all of which need to be made into a twisted curved panels, profile frames are not coplanar straight line splicing.

 

3.Technical analysis of large-surface unit curtain wall

The structural space frame of the project is outside the curtain wall, and the main steel structure is only 400mm away from the glass surface of the curtain wall. The unit body can not be installed as a whole needs to be disassembled in the height direction of the unit body for the visual part and the interlayer part of the two units, the first installation of the interlayer plate, after the installation of the visual plate.

The design adopts four hanging points to ensure its structural stability and feasibility. The upper beam is consistent with the common horizontal sliding unit curtain wall, and the lower beam is designed with two complete sealing lines.

For the upper node of the standard position of the interlayer unit, its design is characterized by: the visual plate falls on the interlayer plate, pay attention to the left and right limit, the limit for the column wall card into the beam on the preset notch, the left and right reserved 2mm range of activities, the visual plate can be able to go around the support point activities.

For the standard position of the interlayer unit under the node, its design features are: the installation of the visual plate in the position does not need to install the L code to cut a section of slightly larger than the L code pieces of the notch, that is, the blue labeled parts of the figure; L code plugged and slid to the required position (ends + middle), the two ends of the L code to play the structural support, the middle of the L code in order to prevent the sealing piece warping; stuck into the through the length of the sealing piece with the strip of sealing, sealing the piece of sealing between the sealing glue, forming a continuous sealing band. The sealant is applied between the sealing sheets to form a continuous sealing strip.

In the design of the interlayer panels, the panel solution at the cow leg is particularly important.

Because of the pre-existence of the structural bull’s-eye, the plate can only be split into beams on-site docking unit, and waterproofing between the unit and the bull’s-eye on-site installation, pay attention to ensure that the position of the visible plate columns have hangings, to avoid beams to withstand the concentration of force.

 

4.Visual unit body plate design

visual plate lower end sits and stands on the interlayer plate, the upper end is stuck into the interlayer plate, and has no hanging joints of its own. Because of the outdoor structural space frame, so only indoor replacement of glass. The design needs to pay attention to a few key points:

(1) the plate through the slot left and right limit;

(2) for vertical to the curtain wall of the buckle plate, must need to be mechanically anti-dislodgement, to avoid typhoons under the buckle plate fall off.

 

5.Frame system technical analysis of

the frame system, is a system of small units with a steel frame keel based on an exoskeleton space frame, the maximum span for the width of 8m × height of 12m, as shown in Figure 10, in which the light blue for the visual panels, dark blue for the back of the structural panels.

The arrangement and optimization of the steel frame is the focus of this system. With the transverse keel as the main stress keel and the vertical keel as the secondary stress keel, the support points are extended on the outer skeletal space frame to reduce the compartmentalized width to 8m × 4.7 m. For the detail part, the water break design of the small cell with 45° splice angle is an essential and mandatory measure for this project.