ARCH 3056 Visual Communication 2 Portfolio University of Hong Kong Minjoo Kim 3035444255
General Information Name Expo Dach Completion Date 2000 Location Hannover Architect Herzog + Partner BDA, Thomas Herzog, Hans Jörg Schrade, München/D Structural Design IEZ Natterer GmbH, Wiesenfelden; Ingenieurbüro kgs, Hildesheim Function An architectural sculptural compositionas an exhibition pavilion, as well as outdoor areas and bodies of water, were created under the shelter of a large roof Span
1600 square meter
The tapering tower structure consists of four silver fir Structural System trunks and triangular bracing panelsof glulam. The beams that cantilever nineteen metres are hung from a steel pyramid that forms the central connecting element. The loads from the ribbed shell and the cantilevered beams are directed into the steel pyramid, and from there to the tower construction. Geodesic curve structure Double-curved lattice shells, each supported on a central structure
Structure Analysis
Plan Drawing
Exploded Drawing
Section Drawing
Detail structure systems under roof
One structure contains 4 shells, 4 cantilevers, the central steel structure and the tower construction. The shell areas show a double contrary curvature and carry the loads forward to the edge girders and the steel structure. The wooden canopy is comprised of ten modular elements, each measuring 120 feet by 120 feet (40m x 40m) and installed at a height of 60 feet (20m) above the ground. The elements are timber double-curved lattice shells, each supported on a central structure.This is made possible by the use of the shell capacity as well as the bending capacity. The more than 19 m long cantilever carries two different weights: Firstly the single force by the outer girder at the very end, secondly the continuous load of the shell itself. The lower bent beam follows the curvature of the shell’s edge and is combined with the upper straight beam in the last third of the girder. From outside to inside the height of the girder increases, according to the loads. The tower construction, consisting of 4 columns and triangular timber frames planked with laminated veneer lumber, carries all vertical and horizontal forces to the foundations. A steel joint connects the central steel construction with the head of the abutments. The frames transfers the horizontal forces of the wind and the geometrical imperfections.
Partition Model
First attempt to create the rhino model without using the grasshopper. The shape of the roof and curves are not natural. Also the connection parts are not finalized. The overall details of the sturcture are weak.
Minjoo Kim 3035444255 Expo Dach Roof
Form Study Diagram 1
Geodesics, also called plank lines, can be built out of inexpensive flat and straight boards where bending in the strong axis, is avoided, and are subjected only to bending about their weak axis and to torsion (Pirazzi, 2006). Inversely, “straight strips, ribbons, are geodesic lines that roll out “autoparallel” on a surface” (Lind, 2007) (diagram 1) When two geodesic curves cross, they both share their the normal vector at the intersection point, thus the joint can be built with a simple inexpensive rotational joint. On the unrolled rectangular flat stripe, the location of the intersection is directly taken from the distance along the geodesic, and can be manufactured by simple universal means (diagram 2). For the expo dach, there are also geodesic shell structure inthe shell roof. The two geodesic pattern had the additional constraint of intersecting orthogonally in a minimal surface. The complete roof thin shell is discretized in prefabricated modules. More recently Toyo Ito architects have implemented the same structural technique for a large roof, with the particularity of having three families of geodesics flowing along a continuous surface. This research stage for the form study of expo dach helped me to understand the structure better and use more aaropriate plugins for further stage.
Diagram 2
Diagram 3 is simple study to understand the geodestic curve and different kind of surfaces that can be generated through same number of points in rhino. Most left surface is the expo dach surfaces and others are surfaces with different curvature lines.
Diagram 3
Grasshopper Construction detail with grasshopper 1. Shell Roof
I used geodesic plubin to create the lines inbetween the curves. I divided the curves in to 11 points and connected them together in right direction (see figure 1). This is shown in first and second procedure photos. The geodesic curve plugin creates smooth arc inbetween divided points. Figure 2 shows the method of extruding the curves to show the thickness of each curves and this is shows in third progress steps photo. Lastly, I created outer curves of the canopy. The thickness is about twice thicker than the inside curves, shown in last progrss steps photo
Figure 3
Final model of 1/4 shell roof Figure 1
Figure 2
Progress Steps
Grasshopper Construction detail with grasshopper 2. cantilever
Figure 4
Figure 5
After shell structure, I made cantilever in between shells that connected to the tower. This bridge structure was simple but have triangular shape supporting structure at the bottom. Figure 4 shows how to create the inside rectangular shapes. I divdied the outer curves and connected with lines. Then extrude in x and y direction to have the thickness. It shows in the first photo of progress steps images. Figure 5 demonstrates the triangular shapes. I spent some time to figure out how to create 3 points lines. I made 3 curves first and connected them in with lines. Then, extrude in z and y directions to show the thickness. I believe kind of detail might would help to improve the quqality of structure. It is shown in second and third progress steps.
Final model of canteliver
Progress Steps
Figure 6
Figure 8
Figure 7
Grasshopper Construction detail with grasshopper 3. Inside
Inbetween the shell roof structure and the tower, there is inbetween support. There are two rectangular structures (see Fig 6) as a base of the structure. I had hard time on creating an extruded shape by using the grasshopper. I used flatten button to enable it. Figure 7 illustrates the connection pipe inbetween the rectanular shapes and figure 8 shows the connection between this structure and the shell roof. Lastely, bottom part of the figure 8 is about connection with cantilever.
Final model of inside structure
Grasshopper Construction detail with grasshopper 4. Tower
Figure 9
Final model of Tower The last part of the model was tower that supports all the above structures. The 4 long columns and triangular shapes inbetween the columns help to connect them. This was fast and easy stage by just connecting the points to make lines and pipe them (shown in figure 9). Then, creating cross lines for the traingles and connect them by usingW 4 points surface tool and extrude them little bit in y direction. (shown in figure 10)
Figure 10
Final Model
Section
Detail-1
Plan
Detail-2
Other Assignments: A2 Paper Model A3 Surface Analysis A4 Modular Stucture
Kim Minjoo 3035444255 Glass Cup
Assembly process Nonagonal modular arrangement
Final structure close-ups
Negative and positive modules
Square and triangular void points
Anticipated curvature form
Final Design Implementation of concavity and convexity The structure consists of concave and convex curvature that allows the modular structure to undulate and vary. This was achived through the different degree of bending between module A and module B. Organic form and various curvature The structure references an organic form previously indicated from the curvature analysis. There is a symbiotic change between the two degrees of bending, and the circular arrangement made from module A and module B. Square and triangle void points The structure comprises two types of void points, square and triangle. This made the concavity and convexity of the structure possible.
