Technical creativityby Anton Miserachs et Pilar Navarro
TP Architectura i Construccio Tèxtil is a company that has been exploring for 30 years the technical possibilities of inflatable and textile architectures. Companies at the origin of the manufacture of inflatable projects AZC, they tell us their evolutions and their rejection of standardized projects in favor of a "technical creativity".
TP Arquitectura i Construcció Tèxtil is a family business specialising in textile constructions. We were set up 30 years ago by Ton Miserachs and Pilar Navarro in Catalonia. Our aim has always been to offer a personalised service. By refusing to manufacture in series and turning down projects for standardised constructions, we have been free to concentrate on technical creativity, with each new project a new challenge.
We are constantly looking for new materials and technical innovations that allow us to respect architects’ and designers’ designs while proposing technical improvements. From the outset we have worked closely with Professor Ramon Sastre, PhD, Architect, and the Universitat Politècnica de Catalunya. These relationships allowed us to benefit from the very first software for the calculation of tensile and inflatable structures, WinTess, developed by Ramon Sastre. As the software has been improved and refined, he has involved us in every stage of its development. From being a system that required new calculations for every stage of the process, WinTess has become a genuine design and construction tool (CAD/CAM) providing support for our skills.
With the benefit of experience, technical improvements and an increasingly qualified team, we have been able to diversify our activity. Now working alongside some of our children, we began developing a series of renewable energy solutions in 2009, specifically in the biogas sector under the brand Upbiogas. Once again we recognised the importance of innovation and, in collaboration with the university and Ramon Sastre, have developed the world’s first software for calculating roof structures for biogas digesters. We have managed to rationalise and reduce risk in the calculation and dimensioning of every element for the development of single- or double-membrane roofs for digesters. The software is very complete, offering calculations based on stresses, anchorage, storage volume, gas pressure and pattern-cutting for particular roof geometries.
As the company has developed, our research has particularly concentrated on managing the energy consumption of the pumps used for inflation. As a result, we have rejected stitching in favour of high-frequency welding, often double welding. A testing system currently under construction will allow us to test resistance and air-tightness before installing a roof. This process will enable us to increase the resistance and durability of the welding, but also to control internal pressure because there will no longer be any air lost via the holes made by stitching. So we are producing inflatable structures that are more or less airtight, with pressure control. Air pumps will function only when necessary. In this way, the volume of air inside the structure is not affected by external loads and tension, which is essential for withstanding wind or snow. Being able to control all these parameters means that we can precisely define coefficients and the limits of resistance and establish a security protocol. We work with textiles that are 100% recyclable, even at the end of their life. Following the establishment of the Texyloop system, even the smallest pieces can now be recycled. What motivates us at TP Arquitectura i Construcció Tèxtil is the creation of one-off pieces that are lasting and safe, the product of our long years of experience.
We originally came across pictures of the Bouncing Bridge on social media. We were really impressed with AZC’s project and naturally wanted to track them down to congratulate them and to propose our collaboration. It is unusual for people outside of the world of textile constructions to conceive a project that is striking in its design and almost entirely realisable. AZC’s reply was immediate and we quickly got to work making a first prototype at 1:10 to test the behaviour of the inflatable structure and the trampoline mesh. A second model at 1:3, produced thanks to updates to WinTess, confirmed the viability of the project.From the first picture we saw of the Bouncing Bridge we were certain that this project was realisable. There was plenty of work to do and technical issues that needed resolving before that could happen, but most importantly the design fitted with the materials to be used. The Bouncing Bridge adventure has introduced us to two architects who, in their experience and professionalism, share our attitude to life and work. They are in touch with the child in us all. They’re driven by their emotions, which allows them to listen to their craziest ideas – like the one to build a bridge for bouncing on. A trampoline bridge? Why not!
The Peace Pavilion
The Peace Pavilion benefitted greatly from the tests carried out for the Bouncing Bridge. We were already aware of the capabilities of each of the project’s participants. That allowed for a real dialogue to be established: the designs were developed as the technical team modified and checked them. This time we knew that we wouldn’t be able to make any test models. WinTess was very useful for conceiving this project. Following his experiences on the Bouncing Bridge, Ramon Sastre developed the software’s capabilities, tailoring it to requirements. Despite its apparent simplicity, the Peace Pavilion demanded a rigorous approach because the beauty of its shape stems from the infinite variety of perspectives it offers. One never knows with an inflatable structure whether one has succeeded until it is inflated. During manufacture it is little more than a pile of fabric. Once the design is defined, we have to be meticulous in the organisation at each stage of the manufacturing process. The roof of the Peace Pavilion, a surface area of 49.8 sq m, was made from 132 pieces. It was a real challenge to calculate this canopy, made in pre-tensioned PVC. The shape’s complexity required precision to the millimetre to avoid any folds. Thanks to the performance of the pattern-cutting software, the precise cutting by numerical control and the quality of the welding, we achieved the perfect dimensions. In textile architecture, pre-tensioned PVC usually deviates by 0.5%. That means that the roof needs to be 0.5% smaller than the structure so that it will attain the correct dimensions when it is under the necessary tension. Unfortunately, at the pressure required for the structure, the diameter of the tube increased by 1% and required us to modify the dimensions of the roof. Using the final dimensions, we tested various loads in order to verify rigidity and define the dimensions of the roof in pre-tensioned textile. The Peace Pavilion is a jewel. Its design is very beautiful, very simple, and very delicate. Realising it required the most advanced technologies and all the skill that comes from many years of experience.
The Flower Pavilion
The Bouncing Bridge and the Peace Pavilion are both integral objects. To build them requires the assembly of a number of different pieces but once constructed they become one single element – an inflated tube – that is both horizontal and vertical, wall and roof. The unity and apparent simplicity of the object make both these projects very appealing. The Flower Pavilion is a more architectural project. It takes its inspiration from nature – a flower – to which it adds a material dimension while maintaining the feeling of a natural shelter. Our design needed to be stable, easily disassembled and transportable. To convince the client of the project’s feasibility, we decided to make a prototype. The project’s complexity derived in part from the assembly of the vertical posts with the horizontal roof, each having a different function in terms of forces, and in part in designing the metal structures that encircle the inflatable modules of the roof. Curved structures, like the petals of the pavilion roof, require a particular level of precision because the deformation forces they are subject to are more complex. Plus we had to consider the affect of air pressure on the petals when they are inflated, particularly because the climate in Berlin would require a high-level of air pressure. In order to be able to fit the different petals together and anticipate water run-off, we had to minimise any deformation. Although the shape of the petals themselves was good for working in compression, we nonetheless planned for a thick frame to ensure minimum deformation. When we inflated the various petals, the forces were incredible and we had to reinforce the metal joints that linked the frames because they were deforming by several millimetres more than anticipated. Following adjustments to the pressure and the thickness of the frames, we were able to get the roof right.
In addition to its technical success, the project generated immediate enthusiasm. During testing near our premises, the children of the neighbouring village, intrigued by this flower, quickly came to join us. We made the most of their energy to test the solidity of the pavilion by getting them to bounce on its inflatable roof. And an engineer friend who teaches agronomy at the Institut la Garrotxa in Olot, wanted to use the project for the Temps de Flors festival, which each year fills the city of Girona with flowers.