Seismological Observatory

Mårten Nettelbladt

Diploma project at the School of Architecture, KTH, Stockholm.
Tutor: Weronica Ronnefalk. Examiner: Staffan Henriksson
Presented in October 2001 to a jury consisting of:
Helle Juul, Christer Malmström, och Per Olaf Fjeld.
(Denna sida finns på svenska)


Brief

Brief

Seismology

Co-ordinate system

Developable surfaces

Cylindrical models

Poly-conical models

Wire

Sketch methods

Hagfors

Conceptual model

Rapid prototyping

Plasic model

Assembly

Volume studies

Form studies

Unroll

Typography

X-ray

Background

 

  BRIEF
Enlarge image DIPLOMA PROJECT . For me, this was an opportunity to study something that really interested me. I wanted to embark whole-heartedly upon an investigation without knowing necessarily where it would end. It was also a chance to tie together what I had learned during the course of my studies.
Enlarge image FORM. I am fascinated by organic shapes and have sought in my investigations to find forms on the dividing line between free-form and the geometric. I have also tried to find a ballance between complexity and simplicity.
Enlarge image CONSTRUCTION. Organic form can often be hard to produce in a larger scale. What can be modelled easily out of clay or in computer software, may prove to be too complicated for traditional production methods. Therefore I have tried to find a technical system that could create free forms more easily.
Enlarge image TOOLS. While sketching I have used various techniques for modelling, including paper, clay, wire and computer software. I find it important to work hands-on during the sketch process and let the tactile sense complement the eye in the assessment of forms.
 
Enlarge image CONTRAST. Disastrous and unrestrained natural force is reduced in the seismological instruments to a settled oscillation registered with great precision. The chaotic, devastating and unpredictable meets the orderly, controlled and formal. The whole earth shatters, but the measured movements are microscopic.
Enlarge image NUCLEAR WEAPONS . When a nuclear charge explodes in a bore hole underground, great amounts of energy are set free. In a split second the pressure increases thousands of times and the temperature rises many millions of degrees. The surrounding rock evaporates, creating an expanding spherical cavity.
Enlarge image SEISMOMETER. Any instrument measuring the earths vibrations is based on the law of inertia. A load is suspended on springs in such a way that it lags behind the movement of the ground. This difference is registered and the information stored for later analysis.
Enlarge image HAGFORS. The northern parts of Värmland are considered the best place in Sweden for seismological observations. Not only is the bedrock hard and free from cracks, the area is relatively far from the ocean and major cities, which reduces the level of background noise in measurements.
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  SEISMOLOGY
Enlarge image EARTHQUAKE. A major earthquake doesn't only set the surrounding ground rocking; shock waves are spread across the earth through its crust and centre. With sensitive equipment these vibrations can be registered and used to analyse both the quake itself and the interior structure of earth.
Enlarge image NETWORK. By comparing readings from many different places on earth, the location and intensity of the quake can be determined. Seismological stations are spread all across the world and most of them are part of a network.
Enlarge image ARRAY. It is also possible to place a group of seismometers in an area, the distance between two instruments can range from a few hundred metres to several kilometres. This is called an array and gives more distinct and detailed information than a single seismometer.
Enlarge image TREATY. Because an underground nuclear explosion causes similar vibration to an earthquake, it can also be registered with seismological equipment. Since 1995 there is an international treaty to ban testing of nuclear weapons signed by a majority of the countries in the world. A control system has been set up and seismology is one of the methods used to discover new tests.
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  CO-ORDINATE SYSTEMS
Enlarge image INTRODUCTION. Positions on the earth's surface are normally described in terms of angles relating to the equator and the zero meridian; within a city region, the location of different areas can be easily expressed in terms of direction and distance from the city centre; when we describe things in our immediate vicinity we prefer to use relative terms (over, under, in front of, behind) that relate either to the own body or some other reference point.
Enlarge image CIRCUMFERENCE. To sit down in a comfortable armchair can give the sensation of a form created to fit the body. This is even more evident when putting on a piece of clothing of the right size. It is sometimes possible to get the same feeling in a building, when a room or a detail appears to fit around the body without there necessarily being a physical contact. I find these experiences valuable.
Enlarge image ORTHOGONAL. The perpendicular, orthogonal system divides space in three directions (along the axes called x, y, z) where every point can be described by three co-ordinates. Space is cut up into cubes in a very efficient way, which makes any part or position equal to every other. There is a theoretical centre (origin) but this has no real practical importance.
Enlarge image POLAR. In a polar system, points in space are described by giving the angle and distance to a reference point, a pole. A sphere can connect points with equal distance to this origin. In this system, space is differentiated and constantly related to the pole.
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  DEVELOPABLE SURFACES
Enlarge image DEFINITION. Forms are called 'developable' or 'single curved' when they can be created through ordinary bending of a planar surface without stretching, cutting or wrinkling the material. These surfaces are characterized by only bending in one direction at a time, like the cylinder or the cone. Developable surfaces are useful because they allow round forms to be made out of flat materials like plywood, sheet metal or cloth. This is why they are used for ship building, tent sewing and fabrication of ventilation ducts etc.
Enlarge image DOUBLE CURVED. Surfaces that bend in two directions at the same time and cannot be made out of a flat material are called 'double curved'. The sphere and the saddle are examples of such surfaces (no double curved surfaces are developable). 'Ruled surfaces' are constructed from straight lines and are either developable or double curved. Because they appear to be straight in one 'direction' they can be mistaken for developable surfaces when they are in fact double curved.
Enlarge image TYPES. I have found four types of developable surfaces:

1. Cylindrically developable. A curve extruded straight, creating a surface with a constant section. If the curve is a circle, the surface will be a cylinder.

2. Conically developable. A curve extruded towards a focal point results in a surface with a section varying in size. A circle shaped curve produces a cone.
Enlarge image 3. Poly-conically developable. Surfaces of the two first categories joined together create a composite surface consisting of conical (and cylindrical) segments.

4. Super-poly-conically developable. If a poly-conic surface (type 3) changes focal point momentarily, the resulting surface curves in a smoother way and can no longer be divided into segments.

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  MODEL STUDIES
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  CYLINDRICAL MODELS. These models were created in computer software and then built out of paper. Several cylindrical solids were grouped to intersect each other in different ways and then subtracted from a larger solid to create spaces. This method was very fast but the result arbitrary and unpredictable with complicated junctions at sharp angles.
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  POLY-CONICAL VOLUMES. These models can be called developable approximations of the sphere. If an upright square in space is rotated horizontally around its own centre the result is a cylinder (04-0). If the cylinder is split and one half is rotated 90 degrees, the result is the volume in figure 04-1. In the same way the hexagon formed 06-0, the triangle made the cone (03-0) etc. By rotating one half of the original volume, its different surfaces are joined into poly-conical surfaces, reducing the number of surfaces. 08-0 is made out of five pieces and 08-1 only two. These volumes are interesting because they show possible ways of constructing spatial volumes in a way that limits the number of consisting parts. As a comparison the cube is made out of six surfaces.
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  WIRE. These models were invaluable for understanding developable surfaces. First I created a figure out of wire and then tried to cover it with paper.
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  SKETCH METHODS
Enlarge image PAPER. The most obvious way to investigate developable surfaces is to bend a flat material and see what forms can be made. A piece of paper can be cut at random and step by step be made to fit another piece. Though time consuming, this method is great for improvisation and finding new solutions.
Enlarge image WIRE + PAPER. Another approach is to first make a wire frame and then cover it with paper (see more images above). In doing this it becomes clear that two curves cannot always be connected by a developable surface and also exactly how these curves need to be shaped to make it work. This method offers perfect control over the intersection between two surfaces, namely the wire.
Enlarge image CLAY. To quickly sort out a spatial relation or test a new idea, a piece of clay can be very useful. One disadvantage is of course that the material is not in itself restricted to being developable (as is paper).
Enlarge image CAD SOFTWARE. In a computer model surfaces are easily edited and moved and they maintain their position in space without support. If something is in the way it can be temporarily hidden and the model can be viewed from every imaginable angle. The surfaces of the model can be flattened (unless double curved), printed on paper and rapidly assembled to a prototype. The biggest disadvantage with computers is that the screen lacks depth and the mouse only moves in one plane resulting in a poor three-dimensional sense for the model.
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  HAGFORS
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Enlarge image TENT. A photo from the site.
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  CONCEPTUAL MODEL. This model was made out of two pieces of plastic joined by a continuous seam. It shows the main features of the building with transparent and opaque surfaces, the three supports, the sensitive measuring equipment and the organic forms meeting a more regulated geometry.
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  RAPID PROTOTYPING. By only using developable surfaces a computer model can quickly be turned into a physical one. It is so much easier to get an idea of the form when the model is in your hands rather than on the screen
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  PLASTIC MODEL. A model of the final building (at scale 1:25).
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  ASSEMBLY
Enlarge image EXTERIOR. The building rests on three cushioning supports that are screwed directly into the rock. The outer cover is composed of different pieces of bent polycarbonate plastic, some transparent and some translucent. Details like openings and fittings are made of stainless steel and screwed into the plastic. The exterior is fairly symmetrical, relating to the three supports.
Enlarge image SYSTEM. I have tried to fins a building system that would make assembly on site very easy in spite of the complex forms. The sheets of polycarbonate are cut in a workshop by a programmed laser cutter. Openings are cut out and the pieces are marked. The pieces are made in different thickness depending on their position and amount of bending. Some smaller and planar details are welded in the workshop.

Enlarge image INTERIOR. The building's interior is also made out of bent pieces of polycarbonate. In a centrally placed hole in the floor there is access to a concrete foundation cast directly onto the rock. This is where the seismological equipment is placed. Indoor the forms are more organic, trying to approximate the spheres and cylinders that illustrate different functions and movements in the building. Because the building is very lightweight and only has three supports, balance was an important factor for the spatial organization.
Enlarge image JOINING. The building parts are transported to site and joined together by thin cable. No templates or supports are needed to give the building its right shape, the pieces are simply bent (elastically) until they fit each other obtain the right form 'automatically' when put together. The plastic itself is the supporting structure.
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  VOLUME STUDIES. Made in the software Rhinoceros.
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  FORM STUDIES. Made in the software Rhino.
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  UNROLL. Examples of forms that are unfolded to planar surfaces. (Bottom right is the Japanese software Tenkai).
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  TYPOGRAPHY
Enlarge image As a sidetrack I used one day to design these letters and figures. They were intended for the stylised map of the measuring points.
Enlarge image The letters were to be milled into the aluminium hatches and therefore needed to be simple.
Enlarge image If the two arcs in 'B' were made equal, the upper one looked bigger. I tried different proportions to compensate for this. 5:6, 9:10, 11:12, 14:15. At 20:21 I thought they looked equal.
Enlarge image The stylised map over the array of measuring points, where 'B1' represents the actual building.
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  X-RAY. The man next to me on the plane was working on a PowerPoint presentation about artificial hip joints. The x-rays showed the tissues in varying clarity, some parts were barely visible. The metal of the prosthesis appeared with incredible intensity and focus. In raptures over the beautiful images I tried to create something similar in the computer.
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  BACKGROUND
Enlarge image IDEA. In a quick sketch from a previous school project ('Överjord - underjord', autumn 1998) the idea emerged of a seismological observatory, deep down in the ground.
Enlarge image SKETCH. My first drawings in the Diploma work sketch book. From a museum in Alice Springs, Australia, January 2000.
Enlarge image TWO SIDES. In the weekend supplement of Dagens Nyheter there was an image of Palestinian street fights and on the back side an advertisement for a web guide. By folding the page I could see both images at once. To me they symbolized the two sides of seismology.
Enlarge image WORKROOM. My place of work during the diploma project: the apartment in Vårberg, Stockholm.

POSTER. This is what the presentation looked like in October 2001. (3276x1054 mm 1.6 MB)

 
 


Omkrets arkitektur. Page updated in July 2007.
(c) Mårten Nettelbladt, October 2001. October 2006.
This text was originally written in Swedish. Translation by the author,
apologies for any spelling mistakes and grammatical errors.