Mon, 07 Aug 2017 08:57:11 +0100 FeedCreator 1.7.2 http://www.tensinet.com/database/viewProject/4532.html As with all building projects for UN organisations, strict regulations applied for the WTO project with regard to energy efficiency. The tender stipulated compliance with the Swiss MINERGIE-P standard defining low-energy construction methods. The permissible values correspond with those for a 3-litre house (heating oil consumption averages only 3 litres per square meter per year). The original building�s open inner courtyard planted with trees now features a transparent roof made of pneumatically-supported, triplelayered foil cushions affording extremely good heat insulation properties. The foil cushions were calculated and constructed by Swiss company Texlon, aspecialist in hangar construction as well as foil and membrane constructions. The roof is formed of a total of 104 triple-layered foil cushions of which 22 feature an opening mechanism. The cushions lend the domed roof a distinctive curved form. Due to the special steel support structure, Texlon calculated a total of 26 different three-dimensional cuts and forms for the foil cushions of around 3m x 3,5m in size. For the WTO roof, Texlon sought to further develop the profiles commonly used. This further development enabled the fitters to make fine adjustments while clipping the foils in place as well as allowing for easier re-tensioning. These foil cushions weigh about 95 percent less than a comparable glass construction, and their extremely fine support structure enables unbroken views of the skies over Geneva. The foils allow both visible light and the ultraviolet UV-A light essential to plants to penetrate virtually unfiltered. The foils were extruded by Siegsdorf-based specialists Nowofol Kunststoffprodukte GmbH & Co. KG. The NOWOFLON ET 6235Z foils come in a thickness of 12-300�m. This high-performance material from the fluoropolymers family affords virtually universal chemical resistance and meets the B1 fire class criteria (according to DIN 4102). Fri, 28 Nov 2014 12:07:03 +0100 http://www.tensinet.com/database/viewProject/4589.html Norway is well-known for its unspoilt nature and deep fjords, and now too for a special tunnel. Of course, the tunnel itself is underground but a striking ventilation tower has now been added to the city skyline of Oslo. Like many large European or world cities, the Norwegian capital also struggles with rising levels of traffic and the air pollution associated with it. Especially affected are major intersections, and as the traffic increases so the skyline changes � in the case of Oslo, however, in a positive way. The Norwegians were very keen to come up with a solution which demonstrated the Scandinavian lightness of touch, blended naturally into the landscape, and made downtown Oslo a little more peaceful again. The Norwegian Highways Authority drew its own conclusions and constructed a much utilized inner-city tangential beneath the earth. For the obligatory ventilation shaft extracting air from the tunnel, Textil Bau GmbH from Hamburg, the general contractor also responsible for engineering, agreed on a design using technical fabric. Both the client and general contractor appreciated the effect the extracted gases would have on the shaft, so took steps to make the task of maintenance and cleaning as straightforward as possible. With this in mind, SEFAR� Architecture TENARA� Fabric 4T40HF was chosen for its exceptional dirt-repellent and self-cleaning properties. With a membrane surface area of approx. 340m�, a height of 19m, and up to 6.4m in diameter, the membrane tower is an outstanding eye-catcher. A primary galvanized steel construction forms the framework for the pretensioned membrane covering which is secured to the upper steel ring of the structure and to a ring of concrete at the base. Depending on the level of ventilation, the tower must be able to withstand internal wind speeds of up to 20m/s (45mph). For this reason, the membrane is supported by horizontal floating rings � steel rings with hollow square profiles � which form the two central points dividing the membrane into three equal sections. But achieving the desired chimney effect required one more thing: the external membrane tabs at the base also had to be clamped at the angular section to secure a connection to the concrete ring. Only then was the tower airtight. To protect the fabric from vandals, the bottom third of the membrane was surrounded by a fence which will have creepers planted around it, giving the tower a sense of having �grown� within its urban surroundings. To protect the fabric from vandals, the bottom third of the membrane was surrounded by a fence which will have creepers planted around it, giving the tower a sense of having �grown� within its urban surroundings. Fri, 28 Nov 2014 12:02:29 +0100 http://www.tensinet.com/database/viewProject/4429.html Introduction Circular textile roofs usually end up as conoids with a central mast or suspended high point. Nevertheless, other solutions are possible provided that the perimeter is not included in the same plane. For the �Castle� Disco in Santa Pola a circular paraboloid was designed. Description The enclosure is circular in plan, 35m in diameter, including a central dance/stage floor, surrounded by a circular porch with tables, benches and seats. An intermediate space in-between provides either complementary seats or a central dance/stage floor extension. Main entrance, services, bar and other facilities complete the whole scheme. Textile roofs Textile roofs were envisaged for the central dance floor and the intermediate space. The central dance floor is roofed with a concave double curved surface, stretched against a spatial ring, 12m in diameter. The spatial ring is made of two leaning trussed arches supported by 6 masts that follow and reinforce the contour of the dance floor or stage. The intermediate space, 26m in diameter, runs between the arches and the porch. It is divided into two symmetrical parts by the drainage of the central roof. They are attached to the perimeter independently in such a way that either of both parts, only one or none can be installed for sun protection purposes. They complete the space directing the shape towards the centre, assisted by the seams resulting from the cutting pattern. Notice that the cutting pattern is not only a concern for making the form, but it also contributes significantly to the perception of the surface, in this case, directed towards the central dance or stage floor, emphasizing that something (or somebody) important is going to happen there. Steel structure The steel structure is also relevant. There are 4 single CHS masts and 2 three-fold CHS masts supporting the trussed arches. The porch is delimited by a series of 20 double CHS in order to be self-supporting and avoid ties between tables and seats. Design concerns The design of the aforementioned roof was used to reveal the difficulty of most 3D design programs to find in some circumstances the equilibrium form of a physical model of a tensile surface structure. The figures show the perimeter of the intermediate spaces, the surface generated by a 3D design programme, a physical model and a computer form finding made with Easy Demo, Technet GmbH. Notice that the 3D design model is not in equilibrium and is not feasible. Fri, 28 Nov 2014 11:59:44 +0100 http://www.tensinet.com/database/viewProject/4426.html Tensile fabric structures offer possibilities for the solution of urban problems which no other type of structure permits. In the Expo Zaragoza 2008 site (Saragossa, Spain) a 400m long structure has been designed that has turned out to be one of leading attractions of the event. It consists of thirteen pieces of torical surfaces that twist and turn at a height of 17m, taking on the appearance of a river. Technically, it includes some advances in structural geometry and artistically, it stands out due to its formal decoration. With the aim of providing shade for the participants� street we build a partial roof along the 500m of its length in such a way that no element would interfere with the views from the pavilions to the street or obstruct the route where various activities would take place. This commission would not have been a problem in itself if it were not for the fact that several limitations existed. We could not place anchorages on the existing buildings because they were not dimensioned for it or in the public walkway as activities which require the street to be obstacle-free were foreseen. The structural and architectural solutions had to be completely stable in themselves with respect to horizontal loading because the pavilions could only provide vertical reactions. These limitations strongly conditioned the final design, which was arrived at by two different paths. The first was conceptual, and consisted in providing the project with a symbolic image. The other was structural, via which we searched for possible forms which would resolve their stresses internally and would convert them exclusively into vertical loads. The conceptual idea consisted of using the exhibition's own leitmotiv, based on water, and building a river which flowed overhead and cast its shade onto the main street. Our objective was to represent Zaragoza's river. The structural idea was based on a self-stressed system which resolves all pre-stresses internally and only transmits to the exterior the actions of gravity, snow and wind loads. We thought that a modular design would help in solving all the problems and modules of 32m x 24m were proposed, with a central part of these comprising 14m x 32m of textile. To prevent the repetition of 13 of these modules from being monotonous, they were mounted in such a way that they curve, as though it were the meandering of a river bed. In order to round off the idea, the textile roof is covered with artistic patterns, which we consider to be a plastic work which combines technique and design, as can be seen in the pictures of the finished project. We wanted the architectural image to be complemented with a design by one of the country's most important artists, in this case Isidro Ferrer. Our main challenge was to achieve a support for the textile fabric surfaces capable of functioning in a self-stress state, that is to say, with vertical reactions exclusively. The horizontal reactions typical of these kinds of structures and arches were avoided with a disposition, where tubular metallic arches would be stabilised by tendons on the upper part of the arches and by cables below them. It is precisely the introduction of these upper tendons which has been special for this project, since an arch is considered to be stable when it cannot open by an outward horizontal thrust, and here the arch cannot expand because of the lower cable, but with respect of the action of the fabric we have also prevented it from closing inwards as it cannot increase its curvature due to the upper tendon. The lower cable works with pushing loads and the superior tendons work when pulling loads are acting. A succession of fourteen arches set at 32m intervals leaves thirteen zones in which modular roofs can be drawn taut. The covers are designed to be seen and to be used as a continuous canopy over the street. The tensile fabric structures used are surfaces of toric geometry (the inner part of a doughnut), 14m wide and 32m long, as mentioned above. The pieces used are limited by two vertical planes and two curves with circular projection. In order to support the curved fabric borders we placed curved steel cable edges at the exterior, which are the fundamentals of the entire structure, as between the self-stressed arches and these border cables or �bolt ropes� (curved edge cables with bolts) a highly resistant fabric is tensioned, which defines our overall design. In order to complete it we dispose another series of cables and rods which are fundamental for the functioning of the assembly but which are barely visually perceptible. The way the arches are supported along the axis is different on the right and on the left side. On the right, they are connected to the roof of the pavilion buildings while, on the left, they are connected to the top of 17m high masts.These masts are of variable cross section and are pinned at their base so as to easily absorb the twisting and bending movements typical in these types of supports for light structures. Masts and arches are rigidly connected, more to facilitate construction than to transmit bending loads. Horizontal stability of the masts is guaranteed by diagonal cables for the longitudinal direction which prevent them from turning over, and with the arches in transverse direction. On the roof, arches are supported directly on the post-tensioned concrete slab at the points where there is a concrete support directly below or on a steel laminated rod to avoid encountering the heads of the tension cables of the concrete slabs. These supports are dimensioned to carry almost exclusively vertical loads and only some small occasional horizontal forces. The arches tensioned on their lower side with a cable and on the upper side with a combination of sticks and tendons are constructed in a polygonal curve made with segments of 400mm x 200mm rectangular pipes where the tensile fabric, interior cables and edge cable devices are connected to. Because the street is not uniform in width not all of the arches are equal. There are two types: arches with a 24m span and arches with a span of 32m, although all of them have the same height of 6m. In order to make the edges of the textile taut a succession of parallel cables was added and connected to a border comprising two parallel cables in a parabolic curve, resulting in a technological solution. Generally speaking, we try to make our designs completely stable in themselves, even when the textile elements are absent. In this way, even if a textile cloth had a structural defect this would not imply the collapse of the rigid elements. Everything that has been said about a self-stressed system works for the interior modules, but not in all aspects for those at the beginning and the end of the street. This is because there are horizontal forces here that can only be absorbed by means of anchorages to fixed points with the transmission of important horizontal components. In order to solve this problem of equilibrium we ran inclined cables to fixed points on the foundations, as can be seen in Figure 13. We chose to connect at places where there were already other types of supports so as not to increase the number of obstacles in the street. On the other hand, as the loads from these cables are tension forces, the performance of the foundations is improved at the points where the walkways between pavilions are supported. The role of the roof is not exclusively functional - providing shade - but it is also an important part of the functioning of the structure. When we installed the textile modules we achieved a total equilibrium of stresses where none of the elements is superfluous and each is indispensable. Nevertheless, certain considerations need to be taken into account with this kind of architecture in tension, and are worth emphasising as design principles: 1. Despite its high resistance under tension, the textile has very little resistance to tearing and rips can occur at the joints. When this happens stability is only lost between cables and the rest remains in place, and normally in good condition. 2. The textile meshes are designed in such a way that they maintain self-equilibrium when the textile is not in place, that is to say, that the absence of textile does not imply either the fall of cables or the collapse of rigid elements. 3. These types of modular structures have to keep functioning even in the absence of a module, whether it is interior or exterior. 4. The stability of these structures is based on the fact that they are in a state of strong internal tension, which we refer to as pre-tension, before starting to introduce any exterior load. 5. The external loads, basically due to the wind, can act in a different way on each element at each moment in time. 6. The wind loads concentrate their energy in gusts and are thus dynamics of very long periods, between 0.5 and 2 seconds, which means that their movements are visible and therefore disturbing. The greater the initial pre-tension to stabilise the whole, the shorter will be the period of vibration. 7. The forms that can work for this type of roofs are warped. This means that they cannot be constructed from flat surfaces except with an adequate cutting pattern. In our case, we opted for a cutting pattern of a transverse type which takes full advantage of the commercial reel width. All these aspects have been taken into consideration in the construction and structural composition of this roof. Along with those already shown in previous figures, Generally speaking, the construction details of this type of cover have been studied in depth and we have turned to previously-known solutions, although a certain degree of innovation is always necessary. Thus the �bolt ropes� (curved edge cables) are resolved with double cables in order to tighten the cables which pull the textile taut and the superior screw threads of the arches are resolved bit by bit by means of a nut at each end. One of the most important aspects of a textile roof project is to program the sequence of assembly and tensioning. In this case we chose to stress the entire metallic mesh previously, apart from the stressing which depends on the existence of the textile. Then it was possible to mount and stress each module in turn, which greatly facilitated the construction process. Moreover, it has been necessary to work in a space full of obstacles, and without priority over other work in the street as far as assembly was concerned. Once the assembly is completed it is necessary to proceed to introduce tension into the fabric until achieving nominal design stress. This is difficult to check in the cables and even more so when it comes to the surfaces. The mechanised techniques which exist for this are not very trustworthy and it is better to operate by approximation on the basis of the reactions as, in the absence of external loads, the overall result suggests an equilibrium which is easy to check. The force applied via the screw threads at the extremes determine what happens in the interior in the absence of wind. For this reason, if we check the reactions of the few anchoring cables we have on the exterior we will be able to make an approximate estimation of what happens to the whole. The analysis of this structure is really quite complicated due to its extension and owing to the nature of its components. Moreover, it is difficult to evaluate the loads and the simultaneity of their action. It is for this reason that we have made separate calculations for the textile elements and the metallic ones. In this way, the surfaces, along with their edge elements, have been analysed using the SAP2000 programme in order to obtain some generic stresses. The supporting elements, meanwhile, have been dimensioned with these previous reactions in order to obtain some stresses and reactions which have served to dimension the entire structure. Without entering into further detail, the loads which have been taken into consideration are wind loads when the wind is blowing at 100 km/h, and snow has not been taken into consideration as this roof will only be used during the three months that Expo 2008 lasts. Posterior to the construction, wind speeds of up to 90 km/h have been measured without appreciating any alterations in the structure, which has served as confirmation that it is an appropriate and successful design. Fri, 28 Nov 2014 11:57:23 +0100 http://www.tensinet.com/database/viewProject/4427.html Lorca is one of the hottest places in Spain. In fact people from site say as a joke Lorca means �calor� (hot) upside down. There are more than 300 sunny days per year, and the average temperature is 20�C. So the goal of the open-air mall was to create shaded places with a significant decrease of temperature, to make it comfortable. Food court For the food court, three big conical roofs were planned in order to create vast shadows. At the lower points the membranes are anchored on the roof of the mall structure and the tops are supported by three main masts - one for each roof. The overlapping of the three membranes was designed to create a more dynamic visual result. As an immediate outcome of these ideas and also due to the size of the roofs (each one of the two smaller structures is 800m2 Ferrari 1202 and the biggest is 2.000m2 Ferrari 1302) high loads appeared. This requires a high prestress (more than 2.000kN in some cases) and hence a strong primary structure and heavy duty cables. The final result still seems light within the large spans (in the central roof more than 60m). All the masts and cables were placed exactly on the appropriate concrete pillar heads: some of the anchorage points on the slab were reinforced with additional steel frames and thicker slabs so that the load transmission was correct. Steel plates for masts and cables were installed during the execution of the slabs, to assure a high quality load transmission. Some of these plates did weight over 800kg. The prestress in the membranes and tie down cables was introduced in two ways. At the corner points special turnbuckles were used and at the top of the main masts the position of a floating ring connected to the top was adjusted by tensioning with hydraulic devices. Each membrane was plotter cut and welded into one piece (even the 2.000 m2 one) in our factory, and crane folded in a precise way to allow an easy unfolding on site, at the right position. Cable sizes did not allow using reasonable pocket borders, so a clamping system was designed to allow the installation of the clamps and the cables on the ground, and the uplifting roof by roof in only one operation. Time needed for the installation of the food court roofs was one month, two weeks for the biggest and one week for each one of the smaller. Restaurant Ten more roofs were built for a specific restaurant. They were designed as inverted cones of about 80m2 each, with an eccentric mast, and were manufactured in the workshop and installed in a very fast way since all the system works as a modular kit construction. Membranes were patterned, plotter cut and made in our factory in Ferrari 502 coloured fabric. Installation process on site took only one day per roof. Bowling terrace Finally a 600m2 roof was designed and built for the bowling terrace, following similar criteria than in the food court ones. An articulated central arch created a significant shape in the middle, so it was easy to reduce loads on the membrane and the structures. This roof was made in Ferrari 702, and its geometry and size allowed a common pocket border solution, so the complete roof was designed, engineered, built and installed in only 1 month. Fri, 28 Nov 2014 11:53:28 +0100 http://www.tensinet.com/database/viewProject/4527.html Paturiz Shade Solutions, recently installed a 1.440m� shade structure in Naharia, Israel. The brief was to create a shade structure for a Skateboard Arena located in a windy coastal environment. The company designed a unique structure with a breathable knitted HDPE fabric from Gale Pacific called Synthesis Commercial 95. Due to the knitted construction of the fabric air will flow more freely through the membrane resulting in more comfortable conditions beneath. Paturiz went one step further and designed purpose built holes into the fabric canopy to allow even further airflow to compensate for the high velocity winds. Winds of up to 130km/h are frequent in this region and the holes are designed to allow airflow both from above and below the canopy. This is intended to relieve the stress loading on the overall structure and ensure the long life of the fabric. It also allowed for additional light transmission and created a unique aesthetic element for the design. Fri, 28 Nov 2014 11:52:01 +0100 http://www.tensinet.com/database/viewProject/4414.html The Expo Boulevard is a 1km long channel which is designed to connect the entrances of major pavilions of the 2010 Shanghai World Expo Park and also the elevated pedestrian walkway. Consisting of 2 floors underground and 2 floors above the ground the Boulevard is a large-scale, multi-functional combination of transportation, commercial activities, catering, entertainment and exhibition services. The six 40m high horn-shaped structures of the "Sunny Valleys" divert sunlight into underground levels of the Expo Boulevard and collect rainwater for use after recycling. In these six valleys there are about 10000 joints and every joint has a different angle and position. So the construction has to be very precise. Saint Gobain Performance Plastics supplied more than 100.000m2 PTFE Architectural Membrane for the roofing tensile membrane structure covering the whole Boulevard to create an innovative, spectacular spatial visual effect. Saint-Gobain Performance Plastics is supplying FEP and PFA for welding PTFE fabric membranes and ETFE for film membrane construction. It�s scheduled to be completed by the end of 2009. The Expo Boulevard project is not only a landmark project in the Expo district, but will also be a city landscape architecture of Shanghai in the future. Fri, 28 Nov 2014 11:50:42 +0100 http://www.tensinet.com/database/viewProject/4412.html The three stations of the Shanghai Subway Station Line 6 are covered by 16 inverted umbrellas each. The umbrellas are shaped with a cable borderline at the high point and have a drainage system integrated at the lower part. It is known that PTFE can absolutely not be folded. In the designed configuration it was a problem how to weld the last FEP film seam successfully to make the whole into the shape of an umbrella. The common way is to use aluminium clamps to put the last two welded pieces together and wrap over the clamps some film of the same type. However, the client insisted that the umbrella should be a whole unit and they did not agree to change the way of connection. So when the fabric was being welded and installed we had to find a solution for the following problems: 1. How to make the last welding seam? The last welding seam was welded on site with a width of 10cm. 2. How to manage the installation? First the welding desk was positioned according to the 3D shape of the welding seam, next the welded fabric was wrapped around the steel structure and then it took five minutes to weld the last seam. 3. How to drain the rainwater? The rainwater is evacuated through the bottom circle of the inverted umbrella. The steel columns supporting each umbrella were designed to be equipped with drainpipes and were galvanized inside from top to the bottom to create an integral drainage system that is unperceivable. These columns are connected to the underground-drainage system of the subway station. Fri, 28 Nov 2014 11:48:57 +0100 http://www.tensinet.com/database/viewProject/4440.html Fri, 28 Nov 2014 11:43:20 +0100 http://www.tensinet.com/database/viewProject/4542.html The idea of the architects (grupa 5) was to design a light roof, which would not violate the beauty of the historic Art Nouveau architecture. The new roof was designed as a membrane structure, tensioned on steel arches, which covers the area of four platforms between two old sheds. The structure of the membrane roof consists of 12 similar fields. The dimensions of a singular field are 21x11.40m. The total dimensions of the membrane roof are 84x34.2m. The main bearings elements are longitudinal, perpendicular and diagonal arches made out of tubes with a diameter of 356mm. The shape of the arches refers to the original arches of the German architect Bernard Klusch, built in the years 1899-1904. In the dome surface of the roof, bracing are applied. The roof is situated in a first snow zone, thus total snow load is 1.05kN/m2. According to the requirements of the Polish law concerning snow removal, in the low points of the membrane on the columns, huge openings were introduced. The membrane is attached to the main longitudinal arches on the bottom side. In this way the steel structure (arches and bracings) is visible from the platform only on sunny days as a shadow on the membrane. The use of the translucent membrane (Mehler Mehatop F IV) gives a lot of light to the platforms and brings a friendly and pleasant atmosphere. Fri, 28 Nov 2014 11:42:26 +0100