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Ăœberdachung des Kleinen Schlosshofes im Dresdner Schloss Roofing of the small castle courtyard in the Dresden Castle Cristina Annunziata Rebecca Schulz Simone Appolloni Konstantin Seufert
[A] little castle courtyard Dresden Castle
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Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle Index of content 1. Ideology 2. Bearing Structure: In general 3. Material 3.1 Layer type 3.2 Features 3.3 Acoustic insulation 3.4 Thermal insulation 3.5 Optical properties 3.6 Reaction to fire 3.7 Life, cleaning and maintenance 3.8 Environmental sustainability 3.9 Material strenght 4. Project‘s analysis: 4.1 Plan and section of the Dresden‘s castle 4.2 About the building 4.3 Functional needs and expectations
p. 3 - 4 p. p. p. p. p. p. p. p. p.
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Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle Ideology Starting with the primitive hut, architecture became one of the most basic elements of humanity. Located in the center of a community the fire place was one of the earliest forms of socialization. Later humanity started to build houses around the fire place, to keep themselves warm and to create a shelter. The easiest forms were caves and later tents built of textiles. Author Antonio Averline, better known as Filarete, concentrated himself with the question who could have been the first architect. It is quite feasible that Adam was the first architect. By crossing the heavenly threshold humanity began to perceive. That‘s why they started to build houses. The need of protection, beeing on one‘s own, selfpreservation and so on became important. Some would even say that architecture ist the first essential art form. But in general the story of the primitive hut is nothing else than the idea of a place. Today it is still important to create a place, which protect people and which has a socialize competence. And of course architects have to face with ecologically harmless. [1]
Before the 18th century architects and designers had a natural scientific eye. In their opinion a sentimental optic was not ‚true‘. Things became true only when they were able to come through one‘s mind. The first building which changed this opinion was the Crystal Palace(picture below). The Crystal Palace was a cast-iron and plate-glass building. It was build to house the Great Exhibition in London of 1851. It was designed by Joseph Paxton, an English Gardener and later architect. This fact was very important, because he wasn‘t influenced by the general opinion mentioned before. The building was the perfect example of the latest technology developed in the Industrial Revolution. It was build with prefabricated elements. And it was the largest amount of glass ever seen in a building and it was full of naturcal light coming through the facade. Visitors were able to experience the outside and the inside at the same time. Further more it had an enourmos size. It was 564m long with an interior heigt of 39m. [2]
Gottfried Semper was an German architect of the 19th century. He was focused on theoretical and practical work. In theory he occupied himself with the framework and the sheat of a building. For him a building was nothing more than that. In 1851 he visited the Great Exhibition in London and he was absolutelly impressed by the Crystal Palace. A simple framework and a sheat. In Semper‘s opinion arts and crafts and architecture have the same roots. He claimed that modern materials and constructions were grown of textile arts. This delevopment was the facing theory in movement. According to this theory forms, which were designed by textile arts, were translated into other materials. [1] [3]
[B] Crystal Palace, 1851, London Joseph Paxton
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Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle Ideology (2) To go a step further in the 20th century it was Frei Otto who had the issue to develop buildings with a minimum of materials and in a combination of a framwork and a sheat. Therefore he combined the three ideas mentioned before. In his experiments he tried to work with frame models and soap sud and with grid shells and rope webs. The first one helps to find the minimum of surface. The second experiment was helpful to find the form for a grid shell. He turned the rope web around and stabilized it. So it was possible to work with textiles, different types of shells and steel. He was the first one who tried to involve textiles as a membrane into the building trade although this idea is such a basic one. One of the most important advantages is the less of weight. It was possible to cover a large expanse His most famous buildings are roofings in the form of a tent (image below). This was a very organic form. And they connected the inside with the sphere. Frei Otto also dealed with light like it was shown in the Crystal Palace. [4]
Nowadays some planning offices are able to create membrane structures. It is a very specific know-how which has to face with a lot of different points, for example the relationship between form and material, the assembly and so on. The material is not a simple textile, it is a well-developed membrane like the ETFE-material-a fluorine based plastic. Membrane structures have a lot of advantages. Because of the less of weight it is possible to create large expanses. It is also possible to create mobile constructions which are changeable. This was even an aspect of the Crystal Palace. Membrane structures also become more and more important as facades. There it is interesting to know that the transparency allows to use a bright action of light. [5]
In conclusion we see that membrane structures are enshrined in history. The first steps to build a house had to face with textiles to create a tent. After a period of very heavy buildings and the use of stone structures it was Joseph Paxton who tried to open buildings in 1851 by using modern materials and who offered wide spaces. Later Gottfried Semper focused on textiles in architecture and with Frei Otto in the 20th century it was one architect who came back to the basic idea of building trade. Thanks to this we can enjoy very specific buildings nowadays.
[C] Olympiapark, 1972, Munich, Frei Otto
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Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle 3. Material ETFE is a fluoropolymer, or a polymer (a macromolecule composed of a chain of identical molecules), which contains fluorine atoms. The basic molecule is the Ethene. Its chemical formula is C2H4. Germany, with 2.9 million tons (1989) is the largest European producer of ethylene, followed by France (2.5 million tonnes) and the United Kingdom (1.9 million tonnes). The main characteristic of the fluorinated polymers, and in particular of ETFE, resides in the fact that most of the chemical bonds present is of type CF (Carbon-Fluorine), one of the covalent bonds with the highest energy. It follows that the molecules are very stable, can sustain high levels of thermal stress and chemical aggression, more than other polymers. Only few companies are able to engage in fluorine chemistry, in which it is required advanced production technology. The main actors in theindustry today are Dyneon, DuPont, and the Japanese Asahi Glas and Daikin. The possible applications of this material, are very large: covering of tanks or pipes,
insulation of cables, photovoltaic cells, acoustic insulation, in aerospace and the automotive industry. Since the 80s is also used in architecture, because it allows the creation of casings totally permeable to light and UV rays.
material increasingly used in buildings, mainly due to its lightweight properties, its high daylight transmittance and the potentials for energy savings. [6][11]
When used as cladding ETFE sheets are usually assembled into cushions, which are inflated (for structural reasons) by means of compressors. The system consists of two or more sheets of foil laid on top of each other and joined at the edges to form the cladding equivalent of an inflatable cushion. ETFE cushions can provide thermal insulation with reduced initial costs and less structural supports is compared with a conventional glazed roof. Designers are currently facing difficulties when carrying out energy optimisation studies as part of the design process. In order to enable building designers to assess the performance of these systems, maximising performance and managing risk, it is essential to gain knowledge and develop methods to model this novel material. ETFE is a relatively new, lightweight
Like a pillow, the pneumatic construction resists external forces through the difference in internal and external pressure. Pressurization: is to maintain regular pressure through ventilation, commonly used in permanent structures. Seal: is pressurised during air inflation only, commonly used in temporary structures such as pavilions. Single layer: fig[E] As with more conventional tensile membrane fabrics the ETFE pre-stress forces define the curvature of the membrane form. Internal stress and external stress work together to make the structure stable. Appropriate reinforcement is necessary as ETFE films can reach yield limits under low-stress and low-strength. Linear thermal expansion coefficient is higher in comparison to traditional building materials. Double layer: fig[F] Triple layer: fig[G] [7]
3.1 Layer type
[E] Single Layer.
[F] Double Layer.
[G] Triple Layer.
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Roofing of the small castle courtyard in the Dresden Castle 3. Material 3.2 Features ETFE has approximately 95% light transmittance, but does not offer the clear visibility/transparency of glass . As a result, ETFE solutions therefore initially found use on projects such as botanical gardens, zoological gardens, swimming pools, and exhibitions spaces. However, ETFE is increasingly finding its place in more traditional buildings as roofing for courtyards, shopping malls, atria and stores. The ETFE material has been used on prominent architectural projects such as the Eden Centre and the Water Cube and it is currently considered for a number of high profile international sports venues. The Etfe, unlike other membranes in architecture, is produced directly by extrusion, is not the result of a weaving. The lack of reinforcement given by warp and weft, and then makes the resistance of the material of much lower than that of other products: the maximum load that a layer of Etfe of thickness equal to 250 microns can withstand is about 3/5 kN / m. This aspect limits the maximum light
of cushions and of tensilestructures in Etfe, The Etfe instead has a good tensile strength: small breaks can be repaired easily with a special adhesive sheet applied directly, without longing to disassemble the structure. Different types of printing on the membrane can vary greatly the transmission of sunlight, for example by limiting the passage of UV rays. This allows to design efficient buildings from the point of view of energy and the thermal comfort of the users. The film can also be produced directly with a tint that maintains a degree of translucency, changing the color of the transmitted light and expanding opportunities for aesthetic and design.[6] 3.3 Acoustic insulation The ETFE is an elastic material, unlike, for example, of glass, the noises produced inside the places are not reflected, avoiding harmful reverberation or echo. This make safe a greater acoustic comfort for users, especially in case of domed roofs or spherical, for which the reverberation effect of the casing towards the fires
geometric, leads to very amplify noises. The external noise, like the rain noise, can be suppressed using a rain attenuation layer added to the top surface of the cushions. This acts as a dampener, stopping the sound reverberating around the space below. In general, the installation of a rain attenuation layer is only necessary in exceptional circumstances. This can be retro fitted to the ETFE foil cushion system and therefore we recommend that rain noise is assessed prior to making a decision to install. [6][8][10] 3.4 Thermal insulation One of the main reasons for using ETFE is the low thermal transmittance achieved for large span modules. While a single ply of ETFE membrane has an approximate U value of 5.6 w/m²°K, a standard three layer cushion can achieve a U value of 1.96 w/ m²°K a better insulation value than triple glazing when used horizontally (glazing manufacturers figures are for vertical glazing which considerably enhances the figures).
[H] Beijing National Aquatics Center, 2008, Beijing PTW Architects, CSCEC, CCDI, and Arup
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Roofing of the small castle courtyard in the Dresden Castle 3. Material The insulative qualities of ETFE cushions can also be improved by the addition of more layers of foil (maximum five in total) or by treating the foil with specialist coatings to enhance the thermal properties. G VALUE: The G value of an installation reflects the fraction of solar energy transmittance through glazing. This is usually expressed as a percentage or a value between 0 & 1; the higher the number, the more energy is being transmitted through the glazing and the more the building will heat up. The G value of an ETFE roof can be reduced to as little as 0.48 for a 2 layer system with a fritted top surface and to around 0.35 by using a 3 layer system. For comparison, standard glass is approx 0.88 whereas some specially treated glass may be as low as 0.46. Usually ETFE cushions incorporate two or three air chambers. Convective heat transfer within these air chambers will influence the thermal performance of the cushion and estimation of U-values is generally complex. Modelling of ETFE cushions as part of building performance simulation is therefore not straightforward. The performance of the systems can be assessed by means of computational fluid dynamics (CFD) and/or by empirical (hot box) testing. [6][9][10] 3.5 Optical properties The transparency of ETFE is equal to 95% for a radiation ranging from 400 to 600 Nm, the spectrum of visible light, with a percentage of scattered light equal to 12% and direct light equal to 88%. A shell consisting of three layers (upper layer of 200 microns, an intermediate layer of 100 microns, bottom layer 200 microns), brings the level of transmitted.
light with vertical incidence to 70%; this value is optimal for the comfort of people, animals or plants. The base material of an ETFE installation is very transparent, however, the ETFE Foil can be treated in a number of different ways to manipulate its light transmission properties. These include: - Printing: Also known as fritting, the surface of the foil is covered with a variety of patterns to reduce solar gain while retaining translucency. By varying the percentage of coverage and density of the ink, the energy transmission can be altered. Alternatively, the foil can be over printed with a number of treatments to affect transmission. We offer a standard range of over 20 standard fritting patterns to achieve this variety of light transmissions, however, bespoke patterns are available at an extra cost. - Tinting: A selection of coloured foils are also available, although less readily than the standard clear foil. Coloured foils can be used alongside clear foil to incorporate branding and large scale imagery. White ETFE foil can be used to reduce glare but maintain some light transmission and insulation properties. - Surface treatments: Surface treatments undertaken during the manufacturing process can vary the properties of the fabric and allow us to manipulate light transmission. These treatments render the foil matt in appearance and therefore provide an excellent projection surface for light shows and images. - Radiation: The foil be conditioned with a range of radiation treatments which can reduce the levels of UV rays transmitting through the membrane skin. Adding additional layers of ETFE foil to a cushion also allows light transmission and solar
[ I ] Coatings in ETFE cushion
Fach Structural Design - combination of cushions and grid framework
gain to be controlled. Multi-layer cushions can be constructed to movable layers and intelligent (offset) printing. By alternatively pressurising individual chambers within the cushion, we can achieve maximum shading or reduced shading as and when required. Essentially this means that it is possible to create a building skin which is reactive to the environment through changes in climate.[8][9] 3.6 Reaction to fire ETFE is a material of low flammability, in the category B1 according to DIN 4102; in case of fire, when the gases reach a temperature of about 200 째 C, the membrane becomes softer, and if it is in tension because of air pressure inside the pillow, the sheet become punctured, and the gas go out. This avoids the concentration of toxic gases inside the building, and that the temperature rises further, which could cause damages to the supporting structure. At a temperature of 275 째 C, the membrane melts down, but not let fall drops of incandescent material; additionally tends not to propagate the fire, thanks to a special property of fluoride compounds.[6][9] 3.7 Life, cleaning and maintenance ETFE Foil has an excellent life expectancy as it is unaffected by UV light, atmospheric pollution and other forms of environmental weathering. While no ETFE structures have been in place for long enough to gain a true understanding of the life cycle of the foil, the material has been extensively researched and tested in a laboratory environment and out in the field. These tests have concluded
[J] Frit in ETFE cushion
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Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle 3. Material that no degradation or loss of strength has ccurred and there is no sign that the tested in a laboratory environment and out in the field. These tests have concluded that no degradation or loss of strength has occurred and there is no sign that the material will become brittle or discolour over time. As a result, it is anticipated that the material has a life expectancy in excess of 50 years. All ETFE structures are designed with curvature to ensure that rainwater does not ‘pond’ or collate on the top of the membrane as this leads to deformation of the foil. Rainwater will be channelled to the perimeter of the roof where it can be collected in the main gutter system. Gutters are not supplied as standard within most ETFE installations but they can be incorporated if required fig[M]. Unlike traditional fabric structures, ETFE Foil is an extruded material and therefore has a smooth surface. This smoothness reduces the amount of dirt retained on the ETFE foil surface and allows the rain to wash away the majority of bird droppings etc. As a result, we advise that ETFE foil cushions are cleaned externally every
2-3 years. The cushions themselves also need to be cleaned internally, although far less often. Depending on the amount of dirt collected in the internal atmosphere, we would recommend they are cleaned every 5-10 years on the interior surface of the cushions. We recommend that the inflation units are serviced every year, however, an active monitoring system is incorporated in all our units which supplies continual information on performance. If a rain attenuation layer has been installed the frequency of cleaning required may be increased but this will vary from site to site. [6][9] 3.8 Environmental sustainability The membrane of Etfe is 100% recyclable. Furthermore, the membrane has a really minimal mass, it is extremely thin: 500 square meters of dual layer of Etfe for example, have a mass of about 0.15 square meters. The raw material associated with ETFE is a class II substance admitted under the Montréal treaty. Unlike its class I counterparts it causes minimal damage
to the ozone layer, as is the case for all materials used in the manufacturing process. The production of ETFE involves the transformation of the monomer TFE in to the polymer ETFE using polymerisation; no solvents are used in this water based procedure. The material is then extruded to varying thicknesses depending on application; a process which uses minimal energy. Fabrication of the foil involves welding large sheets of the ETFE; this is relatively quick and again a low energy consumer. ETFE can be recycled with ease, but due to its properties (does not degrade under UV light, sunlight, weather, pollution) it has a very long life which is estimated between 50-100 years, making the need for recycling small. Excess material from the cushion manufacturing process can be recycled effectively by all ETFE suppliers. The aluminium frames do require a high level of energy for production, but they also have a long life and are readily recycled when they reach their end of life. [6][9] 3.9 Material strenght Based on 250 micron ETFE Foil. fig[O] [9]
[L] Typical section through an ETFE cushion
[K] Gutter Detail
[M] Test strenght Table
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Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis Architects: Prof. Dr.-Ing. E.h. Peter Kulka, Peter Kulka Architektur Dresden GmbH Werner-Hartmann-Straße 1, 01099 Dresden Structural designer: ahw Ingenieure GmbH, Münster Leonhardt, Andrä und Partner Beratende Ingenieure GmbH Am Schießhaus 1 – 3, 01067 Dresden Kröning Ulbrich Schröter Baustatik und Tragwerksplanung Arndtstr. 15, 01099 Dresden Prof. Dr.-Ing. habil. Bernd Dressel Hübnerstraße 27, 01187 Dresden
Project management: Staatsbetrieb Sächsisches Immobilien- und Baumanagement Königsbrücker Straße 80, 01099 Dresden Supervision: AES Ingenieurgesellschaft GmbH, Dresden Building services: Dresdner Ökotherm GmbH Electrical project: Ingenieurbüro Rathenow BPS GmbH Construction of steel grid shell: MBM Dresden GmbH EFTE cushions membrane: Ceno-Tec GmbH, Greven
Client: Freistaat Sachsen Finish construction: 2009
[#A] Site plan
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Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.1 Plan and section of the Dresden‘s castle
[#B] Section of the building B E G GH HAT KH NO NW O S T W WH ZN ZS
Bärgengarten Wing English stairs Georgen-Gate Big yard of the castle Hausmanns-Tower Little yard North wing, east part North wing, west part East wing South wing House of tower West wing Access yard Wing between two parts north Wing between two parts north
[#C] Plan of the building
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Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.2 The Dresden Castle – Past and future Dresden Castle is one of Dresden’s most historically significant and oldest buildings. Almost continuously it has been the residence of the electors and kings of Saxony. Due to its long and impressive history it is also known for the different architectural styles employed within the compley ranging from Baroque to Neorenaissance. One can still find traces of the original castle in the east wing dating back to 1230. In the second part of the 15th century elector Ernst and duke Albrecht converted the once small castle into a representative palace consisting of 4 wings. Elector Moritz, who was responsible for Dresden’s shift to an electoral residency in 1547, transformed the castle in 1548 into one of the most gorgeous renaissance castles in Europe. Between 1590 and 1594 another south annex wing was added. Out of these construction works the Small Courtyard as we know it today emerged. Unfortunately most of the castle’s fittings and rooftops were destroyed during the well-known World War II bombing of Dresden in February 1945 The remainings from this period form the main part of today‘s masonry of walls, pillars and
foundations. At the end of the 19th century the facades and the roofs were reconstructed in neo-renaissance. After the events of early 1945, the castle was lying in ruins for a long period of time despite it’s central location in the heart of Dresden city. For 15 years after the end of the Second World War, no attempt was made to rebuild the castle. Only thanks to the efforts of numerous architects, engineers, art historians, preservationists and citizens, demolition could be prevented and in the 1960s reconstruction and restorations began. A further extensive restoration period started in 1991 with the aim to transform the entire castle into a museum and a place for art and science. In order to be able to provide more space for the large amounts of expected visitors a central foyer space was needed. Visitors to each of the museums and institutions should be welcomed in the small inner courtyard, for which an appropriate solution for a roof structure was chosen in 2002 Prof. Kulka’s proposition was selected among a variety of different designs. The filigree truss dome with its cushions seemed to be the most effective solution regarding its functional, aesthetic and
constructive characteristics..[#1] [#2]
[#D] Plan of the Dresden Royal Palace showing the recently added roof construction cove-
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Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.3 Functional needs and expectations towards design The framework cupola overarch the whole interior space of the courtyard. It is fixed very close to the crest line and it is very good because the pediments and dormers existing buildings are not hided. The structure of the truss dome with crossed diagonal change over the edges in a circumferential edge truss over that on the edge of the dome. stiffened and capable of the bearing forces is at suitable points in the roof structure initiated. Accordingly, the truss cupola is from the grid shell and the edge of truss in the dome base together. The base area of the cupola is 44m x 29 m, height of 8,35 in total, the grid has a height of 7m. The desired transparency of the roofing is obtained by the use oft he air filled foilcushions between the fields between the polygonal lattice girders. The ETFE foil cushions, used for example
in the Allianz Arena in Munich and there have been structuring the exterior, have the advantage of being extremely are easily and adapt well to the warped geometry of the rhombs-shaped fields also do not have the different dimensions. A disadvantage of the use of film in the roofing is connected to the pressure position associated constant maintenance. The air pressure in the cushion must be as scheduled air with leakage rate of about 5% thats why is necessary to use compressors which are able to fill in air constantly. Is possible insuffling the air directly into the hollow profiles of the support structure minimize the costs. The prerequisite is that the air conditioning system is controlled so that neither the pad still in the hollow profiles condensation occurs. To reach a largely regular structure of the grid shell dome in spite of the irregularities in the roof surfaces, the inclination and the distance varies between upper and
lower side of of the peripheral edge truss. It depends of the local conditions of the existing roof structure is the edge truss placed on differently configured nodes. In order as well as in this construction details, such as the storm water drainage optically not appear occur and disturb the overall impression, the edge to the courtyard side truss is blinded.[#3] [#4] [#5]
[#E] Section and fassade of the grid shell dome‘s terminal on the existing roof
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Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.3 Functional and design requirments Examinations to the ambient temperature led to the arrangement of vent holes in the parting of the dome, so ventilation opening at the crest of the roof allow to reduce the temperature of the bearing structure in the summer around 15° K. With rules to the fire protection is to be assumed of the fact that in the foyer, at least with bigger events, more than 200 persons stop, so that the bearing structure would be to be studied in accordance with meeting places-regulation fire-rules. In the result of examinations it was found out, that on a fire-restraining coating can be renounced without remaining under the necessary security level. Besides, two viewpoints played a crucial role: the ETFE folies melt with about 200 °C, so that the warmth can escape with higher temperatures unhindered, and the Frame work dome disposes on account of the extremely indefinite static system of sufficient redundancy with regard to its
supporting effect, so that the local failure of the structure does not lead to the failure of the overall system. For the support constructions in the attics was to be proved according to fire protection certificate, that the sufficient load-carrying capacity for the unusual one alculation situation also then is given, if at least two lying side by side ones bases of the grid bowl fail.[#3] [#4] [#5]
[#G] Cross-section of the stell hollow profile with the cuschions‘ attachment system.
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Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.4 Form creation of the roofing over the existing building The optimization criterion of the form creation was first the minimization of the deformation energy. Over the nearly rectangular form of the edge was stretched a rope net and was loaded with vertical forces. Instead of the experimental form creation with the help of hanging models, it was made by means of nummerischer simulations. Besides, the inquiry of the balance form took place with a suitable arithmetic program. Afterwards the frame work was so modified by the engineer in co-operation with the architects to get an uniform surface appropriate to the pillow forms. This method cause only axial compression forces in the system. Besides, is assumed that the weights have an effect on the structure corresponding at the weights considered in the creation form process and that the support conditions of the structure correspond to the border conditions of the arithmetic model. The frame work dome with its extremely
lightweight roofing with air-filled foil cushions and low self-weight structure, eliminates the effect of a single full shape that determinates an high load situation, So the load is nearly the same to the selfweight of the frame work and it is therefore more balanced but anyway remains the inconvenience of the non-symmetric load on the edges. The main aim during the form creation as well as the structural design of the frame work dome was the load transfer from the new roofing to the static-constructive system of the existing buildings surrounding the small courtyard, therefore both the support forces from the existing building and the load from the roofing should be improved to optimize the functioning of the system. For this reason addictionally to the improvements on the existing element of the castle roof have been provided also new supporting elements without a big boosting efficiency, as well as the
optimization of the dome to keep loads as low as possible especially the horizontal forces. Because of the exterior reaction forces and not the inside cutting forces of the structure were fixed as optimization criterion, was to be expected that the geometry developed during the form creation process was so positive. The forms which are produced on the rectangle edge are characterized by the fact that the synclastic curvature of the central surface goes over in an anticlastic curvature in the corner areas of the perimeter. Surface with changing Gaussian curvature have an effect unfavorably on the stability behavior of shell structures. [#3] [#4] [#5]
[#H] Structural effect: Bearing scheme and resultant horizontal support reaction, perpendicular to the surrounding walls.
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Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.5 Construction 4.5.1 Grid shell The grid shell of the frame work rest on the top of the belt of the edge as lattice truss in an horizzontal plane which is nearly a rectangle with the average side length of 42.3 m x 26.6 m. For aesthetic reasons, the grid shell is constructed by rhombs of the same size, only corner-rhombs are different. The grid is made of steel hollow profiles with a square cross-section 180 mm x 180 mm. The grid nodes consist of steel scheets rigidly welded together forming a cross. Using these crosses is possible to merge profile rods to the opposite unequal section of rod. Moreover, the protruding steel sheets of the crosses contribute to the fact that the unequal planes of section are not perceived optically. Through the arrangement of the orthogonal metal crosses are obtained in each perpendicular planes sectional areas for rod connection.
The attachment of the bars to the steel crosses is made of fillet welds but this should done due to the limitation of the weld thickness and weld voltage limit of onesided fillet welds in accordance with DIN 18800, so the sustainability of steel profile sections are not fully exploited. To fix the air cushions are welded sheet steels vertically outside every hollow profiles of the grid shell. The clamb profiles are appropriated for the membrane cushions. The supply of the cushion with compressed air takes place on the on the profiles of the primary structure and in addition is required in every second grid node a pipe to carry out the air.
may be accumulate condensation, so is arranged an additional holes in the steel crosses.[#3] [#4] [#5]
To prevent condensation in the cushions, the air must be pre-dried, so that adequate corrosion protection of steel construction is guaranteed. When ther is a fault in the air supply it
[#J] Detail of grid shell node
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Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.5 Construction 4.5.2 Edge lattice truss As explained before the base area of the grid shell dome consists of a lattice truce which run along perimeter of the small courtyard. This is contructed with stell hollow profile of circular section, it can transfer the dynamic impuls and absorb cutting forces of the upper canopy with its tie rods, moreover it can help the existing building to stabilize itself and enables to resist to the loads in the areas of the existing roof in which there is not enough load resistance capacity whitout installation of additional structure. For geometric reasons, the supports of the truss dome can not always stay under the nodes of the grid shell, thats why the bottom belt has to face with curvature. Are also arranged addictional rods to provide this problem because of the bottom belt rods can be shorter then. About the design, the bottom belt allow to join the the two different geometries of the framework dome with a rectangular base
and the courtyard perimeter. The lattice truce belt was built combining the different dimension steel rods, those in the corners at the top of the belt are preblending and their radius varies between 3 m and 3,8m, the height of the belt varies between 1.43 m and 3,74 m, however its height on the vertical projection is costant to 1.35 m.[#3] [#4] [#5]
[#K] Canopy structure
Fach Structural Design - combination of cushions and grid framework
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LT Lehrstuhl für Tragwerksplanung TUM
Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.5 Construction 4.5.3 Canopy’s support The grid shell dome over the lattice truss belt rests on some supports placed discontinuously along its sides. These supports, perpendicular to the building walls, consist in elastomeric bearings or pin-ended supports which contrast the vertical forces and permit grid shell dome’s rotations. The elastometric bearings which can also bear the horizontal load as well as non symmetrical wind loads are located in the middle of the base dome’s sides in groups of four or five. Using elastometric support with a definited stiffness of 1200 kN/m each support the existing building’s walls can largely bear the external loads of the dome and temperature action evaluated during the structural design.[#3] [#4] [#5]
[#L] Canopy’s support
Fach Structural Design - combination of cushions and grid framework
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LT Lehrstuhl für Tragwerksplanung TUM
Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.6 Assembling
[#M] Cutted steel bars of the grid shell dome‘
Fach Structural Design - combination of cushions and grid framework
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LT Lehrstuhl fĂźr Tragwerksplanung TUM
Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.6 Assembling
[#N] Mounting of the bar in the workshop
[#O] Assembling of the grid shell
Fach Structural Design - combination of cushions and grid framework
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LT Lehrstuhl fĂźr Tragwerksplanung TUM
Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.6 Assembling
[#P] Assembling of the lattice truce belt
[#Q] Mounted lattice truce belt
Fach Structural Design - combination of cushions and grid framework
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LT Lehrstuhl für Tragwerksplanung TUM
Pneumatic Construction
Roofing of the small castle courtyard in the Dresden Castle 4. Project‘s Analysis 4.6 Assembling
[#R] Mounting of the grid shell on the couryard‘s roof
[#S] Fully assembled roofing‘s structure
Fach Structural Design - combination of cushions and grid framework
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LT Lehrstuhl für Tragwerksplanung TUM
Pneumatic Construction
Roofing of the small castle cour-
Roofing of the small castle cour-
tyard in the Dresden Castle
tyard in the Dresden Castle
List of literature
List of illustrations
[1]
[A] little castle courtyard, Dresden Castle
Wilhelm, Prof. Karin: „Ideen – OrteGedanken – Häuser. Architektur- und kunsttheoretische Positionen zwischen 1850 und 1990 in Europa.“, TU Braunschweig – Fachgebiet Geschichte + Theorie der Architektur und Stadt, 2004/2008
[2]
Samuel Phillips: „Guide to the Crystal Palace and Parkt“, Natl Museums of Scotland, 2008
[3]
Semper, Gottfried: „Die Vier Elemente der Baukunst“, Books on Demand, 2010
[#4] Staatsbetrieb Sächsisches Bau- und Immobilienmanagement; Staatliche Kunstsammlungen Dresden Das Grüne Gewölbe im Schloss zu Dresden, Seemann Verlag, 2006
http://www.invest-in-saxony.net/set/1675/ thumbnails/schlossbild1.jpg.184658.jpg
[#5] Die Stabwerkskuppel über dem Kleinen Schlosshof in Dresden – Synthese von Funktion, Gestaltung und Konstruktion
http://3.bp.blogspot.com/_vzEAuazt42w/ TI6jK_MnLQI/AAAAAAAAAx0/vw664H_ n35I/s1600/crystalpalace.jpg
http://www.kraus-liedert.de/downloads/Aufsatz_Baustatik-Seminar.pdf
[4] Nerdinger, Prof. Dr-Ing. Winfried: „Frei Otto. Das Gesamtwerk“, Birkhäuser GmbH, 2005
[B] Crystal Palace, 1851, London Joseph Paxton
[C] Olympiapark, 1972, Munich, Frei Otto http://www.wackerart.de/Olympia/Olympiastadion.JPG [D] German-Chinese Pavilion, 2012, Shanghai
[5] http://www.dai.org/oeffentlichkeitsarbeit/baukultur/beitraege/555-bauenmit-membranen
http://www.dai.org/images/content/Baukultur/2011-03/Sieder_Shanghai_1.jpg
[6] http://www.architetturatessile.polimi. it/membrane_scocche/prodotti_ mem/2-1_monocomp_edile/2-2_ ETFE_film/ETFE_film.html
http://www.makmax.com/business/etfe_ thermal.html
[7] http://www.makmax.com/business/ etfe_thermal.html
http://www.makmax.com/business/etfe_ thermal.html
[8] http://www.damtp.cam.ac.uk/user/carh5/ Paper%20from%20IBPSA.pdf
[G] Triple Layer
[9] http://www.architen.com/technical/articles/etfe-foil-a-guide-to-design [10] Cecilia Cecchini, Plastiche: i materiali del possibile, Alinea editrice, Firenze, 200 [11] Mazzola C., Zanelli A., Involucri innovativi : l’architettura si veste di stoffa, FRAMES n°126 /2007, Faenza Editrice [#1] Fritz Löffler: Das alte Dresden Geschichte seiner Bauten. 16th ed. Leipzig: Seemann, 2006 [#2] http://www.glas-online.de/glas/ live/fachartikelarchiv/ha_artikel/show. php3?id=32138532&ps_alayout=l_2.inc [#3] Sydram, D.; Ufer P. Die Rückkehr des Dresdner Schlosses, edition Sächsische Zeitung,Dresden, 2006
Fach Structural Design - combination of cushions and grid framework
[E] Single Layer
[F] Double Layer
http://www.makmax.com/business/etfe_ thermal.html [H].Beijing National Aquatics Center, 2008, Beijing PTW Architects, CSCEC, CCDI, and Arup http://catalinamoreno88.wordpress. com/2008/08/26/favorite-beijing-sights/ [I] Coatings in ETFE cushion http://www.damtp.cam.ac.uk/user/carh5/ Paper%20from%20IBPSA.pdf [J] Frit in ETFE cushion http://www.damtp.cam.ac.uk/user/carh5/ Paper%20from%20IBPSA.pdf [K] Gutter Detail http://www.architen.com/technical/articles/ etfe-foil-a-guide-to-design
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LT Lehrstuhl für Tragwerksplanung TUM
[L] Typical section through an ETFE cuhion http://www.architen.com/technical/articles/ etfe-foil-a-guide-to-design [M] Test strenght Table http://www.architen.com/technical/articles/ etfe-foil-a-guide-to-design [#A] Siteplan http://c214210.r10.cf3.rackcdn.com/files/ projects/27406/images/900:w/01---Lageplan.jpg [#B] Section of the building http://c214210.r10.cf3.rackcdn.com/files/ projects/27406/images/900:w/03---Schnitt. jpg [#C] Plan of the building http://www.kraus-liedert.de/downloads/Aufsatz_Baustatik-Seminar.pdf [#D] Plan of the Dresden Royal Palace showing the recently added roof construction covering small inner courtyard http://www.sib.sachsen.de/typo3temp/ GB/9898276508.jpg [#E] Section and fassade of the grid shell dome‘s terminal on the existing roof http://www.kraus-liedert.de/downloads/Aufsatz_Baustatik-Seminar.pdf
Pneumatic Construction
[#K] Canopy structure http://www.peterkulka.de/likecms/ likecms.php?site=site.html&dir=&nav=1&p=1&pthema=4&pid=2 [#L] Canopy’s support http://www.kraus-liedert.de/downloads/Aufsatz_Baustatik-Seminar.pdf [#M] Roofing in the Dresden‘s skyline http://www.glas-online.de/xml-import/bilder/ gls/2009-06/600x/thumb_gls0609dresden01neu_tif.jpg [#N] Cutted steel bars of the grid shell dome http://www.zis-meerane.de/referenzbilder/ architektur/1_4/1.jpg [#O] Mounting of the bar in the workshop http://www.zis-meerane.de/referenzbilder/ architektur/1_4/2.jpg [#P] Assembling of the grid shell http://www.zis-meerane.de/referenzbilder/ architektur/1_4/3.jpg [#Q] Assembling of the lattice truce belt http://www.zis-meerane.de/referenzbilder/ architektur/1_4/4.jpg [#Q] Mounted lattice truce belt
[#G] Cross-section of the stell hollow profile with the cuschions‘ attachment system
http://www.zis-meerane.de/referenzbilder/ architektur/1_4/5.jpg
http://www.kraus-liedert.de/downloads/Aufsatz_Baustatik-Seminar.pdf
[#R] Mounting of the grid shell on the couryard‘s roof
[#H] Structural effect: Bearing scheme and resultant horizontal support reaction, perpendicular to the surrounding walls.
http://www.zis-meerane.de/referenzbilder/ architektur/1_4/6.jpg
http://www.kraus-liedert.de/downloads/Aufsatz_Baustatik-Seminar.pdf [#I]
[#] Fully assembled roofing‘s structure http://www.zis-meerane.de/referenzbilder/ architektur/1_4/7.jpg
[#J] Detail of grid shell node http://www.kraus-liedert.de/downloads/Aufsatz_Baustatik-Seminar.pdf
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