TECTONICS 3 K13 TSB
AKSHEY SHAH
Introduction This semester in studio I have been looking a the symbiotic relationship between the built environment and natural environment. My project is located in Cheshire In a small parish town called Rostherne, 30 mins south of Manchester. The project is an attempt at hydrological isolation of the SSSI site of scientific study, important for understanding fresh water ecosystems. The site is a habitat to many rare ornithological species and a diverse marine ecology. The local microclimate is important to bird life as Rostherne is the largest and deepest mere in the region, consequently the last lake to freeze over in the winter months making it a thriving wetland habitat during the colder months. In the summer due to human dairy and other agricultural activity, fertiliser and pesticides leak into the water table resulting in destabilising natural chemical balance found within the catchment area at the water table mere basin. An influx of Nitrates and phosphates result in ideal conditions for photo algae to bloom in the sunnier months. This can cause uncontrollable Algae that respire removing large quantities of oxygen from the water causing constraints on more complexed marine life in the mere. These entropic conditions cause the water to have a green tinge that can be visible in satellite imagery.
The green tinge shown in this image from google earth shows evidence of entropic conditions In the summer months. feet meters
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This is photographed at the inlet flow to the Photographed at the inlet flow, the orange mere. This white froth occurs when coloration of the plant show excess Phosphate rich water is cavitated. presence of iron in the hydrology .
This Is a map of the tributary inlet flow and the surrounding problematic urbanization and agricultural buildings that results in polluting run off to the mere.
The mere has a defence mechanism to foreign nutrient overloads and other pollutants that enter the mere from the catchment area, reed beds are a natural filter against pollutants. Microbes and bacteria that live in the root rhizomes, these microbes filter and clean the water of excess pollutants. This wetland environment that consist of reed beds and pete bogs is a natural saturated buffer zone between the mere and inflow, acting like big sponges they store water and allow mixing of foreign nutrients before entering the basin.The nature of these wetland zones are very important to the entire fresh water ecosystem as it provides shelter to birds and insects, although these wetlands are constantly under threat in summer months by agriculture that require wetlands to be drained thus drying the mixing buffers zones that the saturated wetlands provided. The receding of wetlands makes way for woodland invasion that results in matured established vegetation such as willow trees competing in spaces that reed beds would otherwise.
This is photomontage showing the different zones in the mere and riparian zones surrounding the mere.
Building program A process diagram for the architectural spaces required for a working building Program to form. Showing the different links between processes and activities Replacement Reed Beds
Observetory
Old
Reed Bed filters
Timber from Woodland Invasion Ree
dB eds
Fog fertiliser
Fog fertiliser
Outdoor prep Storage
Bio Degester
Aerobic Bacteria
Nutrient Rich Water
Fog Fertiliser Processing & Storage
Vehicle Storage
Creating a way of partially isolating the basin of the water table from excess imbalances of nutrients from the sounding agricultural activity, to try and create a microcosm of stable hydrology within the mere basin. Using variable flow diverters implemented on the inflow streams to the mere, diverted water is then stagnated through a series of reed bed filters to remove excess pollutants from the water. The diverted water is then diluted and used to germinate and grow new reed beds onsite to maturity before inoculating the rhizomes with the bacteria and microbes found native to the existing reed beds. The mature beds are then transplanted into the mere fringe, encouraging wetland growth. The reed bed transplanting will occur where land was previously drained for agricultural use, prior to the SSSI classification. The building is a mixed typology with architecture responding to the centralisation of scientific research, maintenance, observation and hydrological isolation of the mere for a collective integration of knowledge to be shared in a small academic and Social community to further the understanding of fresh water ecology.
Reedbeds Riparian zone recovery
Methane
Laboratory Germination Bacteria Farming Chemistry research
Transplanted Reeds, Bateria inoculation
Young Reed Bed growth
Kitchenette
Workshop Foot Bridge Building and cutting Reed Bed Manufacturing (heavily sound proofed)
Toilets
matured Reeds to Contruct Reedbeds
Mature Reed Bed Growth
Reserve Keepers Office
Parking Storage Bike Storage
The Local Bird life inhabiting the mere in the winter months. The mere during the winter has it natural blue tinge.
Evidence of woodland invasion to the reedbed , there is a pruned willow tress competing amongst the reed beds.
Structure Site Analysis The nature of this site is delicate, building construction needs to be surgically transplanted into the environment with minimal impact. The materiality of the building must be inert and non toxic through surface run off. The structure of the building has to be at the fringe of the basin where there is varying water levels thus flood plane structures need to be considered such as stilt or stabilised buoyant platforms. The structure needs to be lightweight, and easy to construct in a short timeframe as to not disrupt the winter birdlife. Construction is limited with large machinery as the surrounding land is marshy and boggy. Looking at lightweight tensile structures made from a composite of fabric membranes and cladding could be an elegant sustainable solution to a building within a SSSI. These light weight structures are easy to assemble in areas with limited construction techniques and have an excellent mass span ratio while using a fifth of materials compared with traditional structures.
Types of Lightweight structures include: Frame Sported structures St Pancreas Station in London These structures are highly adaptable and modifiable, the construction can be fast and with the use of polycarbonate glazing the roof structures can be lighter and minimal to allow for larger unsupported spans. Domes and Free form structures Free standing structures, comprising of smaller polygons held in compression that tessellate to create a freestanding structure. An example of this is the Eden Green house in Cornwall that uses hexagons to form the dome structure. This architectures emerges from how soap bubbles form. This tessellated structure can achieve double curved organic form. Although these structures are generally for large activity spaces unsuited for the scale of my project. Tensile Fabric Structures Cable net structures such as Denver international airport show how building spans can allow for a flexible space with few span supporting structures to restrict the activity in the spaces. Another example of a tensile fabric structures is the atrium space of the Burj al arab this 7* hotel proving although thermal massing is almost non existent in lightweight building structure, use of Phase changing materials and air conditioning are used to achieve luxurious comfortable levels to the internal envelope independent of the large temperature gradient that exists between the inside and outside in the UAE climate. This is done by a 2ft insulation air cavity between 2 layers of fabric. Recent developments in aerogel technology a super insulating material that can be woven in the fabric membrane allows for just one single membrane layer. A frame supported structures will be key to having a lightweight, simple construct and inert building that will have minimal affect on the surrounding SSSI listed environment.
Boat House Structure
Structural System Stilt architecture in flood plane zones keeps the building above the varying basin water level. The building structural core is a steel frame, the main core is then laterally supported by the atrium buttresses that provide a reaction to the cross vaulted arch frame that rests on the opposite side of the structural core. An array of tensioned wires form the outer structure for the membrane fabric that is suspended from the tensioned wires. The wires form hyperbolic shapes that the membrane fabric stretches across to achieves tensile equilibrium. When the fabric is in tensile equilibrium it resists external forces such as wind forces buy distorting and shifting. The tension wires begins at the boat house structure where there are two stability arches that provide a stable triangular structure perpendicular force to tensioned wire direction.
Cross Vaulted Arch Frame
Floor Structure
Structural Core
Atrium Buttress
The building structure is supported by a central core, consisting of a series of columns span. The tall thin nature of the structural core requires buttresses for additional lateral stability on the growing atrium side, The additional functional space grows out from the core structure to the north, where double barrel vaulted arched frame leans against the core structure to increase the building area. The floor is then a series of beams that form a hexagonal lattice, this shape provides rigidity to structural twisting as well as effectively supporting lateral loads exerted to the building. At the envelope boundary, the floor structure cantilevers to form an access around the front of the growing atrium for, servicing and reed bed access Individual wires in tension hold the roof structure in place while providing a resistive support structure for the building envelope fabric to resist external forces. The boat house structure provides a tension anchor for the structural wires. The membrane is then hung from the wires to achieve an enclose envelope.
Building Envelope
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Materiality The frame of the building has to be made from a strong rigid material that is load bearing. A steel frame would be ideal for such a structure as it allows the individual components to be easily cast and then welded or bolted together to form the structure of the building. This allows for smaller components to form larger sections of the building. The floor structure again could be a steel structure as it has excellent structural spanning to create a rigid structure. Conventionally tensile fabric structures have a steel frame.
PVC Coated Polyester
PTFE Coated Glass Cloth
SILICON Coated Glass Cloth
Polyurethane coated Kenaf fiber
ETFE
Life Expectancy
Low
High
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Low
Medium
Strength
Medium
High
High
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Medium
Translucency
Medium
High
Medium
Medium
High (transparent)
Cost
Low
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Medium
The Detailing at the point where fabric meets exposed structure.
The Detailing of the tension components for the roof wire structure
The fabric membrane structure would be made from two of the materials available in the table. PTFE Teflon coated glass cloth is an excellent material for the membrane this project. The durability and life expectancy is high and resistant to UV The translucency is also high, encouraging large amounts of diffused natural light to the internal envelope. Although the cost is high, the scale of the building makes it ideal. The other material to uses in the roof structure is an ETFE film, a transparent polymer that is UV inert, its lightweight nature makes it a good substitute to glass due to is high transparency.
Building environment Ventilation Strategy
Inverted conic tensile fabric structures that were used during the opening of the millennium dome. They were then transported and relocated to be used in Piarco international airport in Trinidad. They are a combination of PTFE and Transparent ETFE
Orientation The orientation of the building is located such that the growing atrium faces south for optimum solar interaction and to maximise growth of reed beds. Both the laboratory and the reed manufacturing workshop required diffused natural light, as a result face north looking onto the mere. Massing of the building is important in a light weight building. The south facing growing atrium is a glazed space with phase changing materials that store thermal energy in the building core. This gives the building a slow thermal response time to prevent large internal temperature fluctuations. The internal spaces are all north facing as they provide an dispersed indirect light throughout the day. The entrance is on The east side of the building as it is sheltered by tress to prevent harsh internal envelope winds.
The building is naturally ventilated. The strategy has a diverted cross flow from the exposed south Meer facing side of the buildings across to the atrium space where it escapes at roof vents. This is driven by the prevailing wind that blows across the mere .
Rain recovery
Facade articulation & Solar shading There is a glazing wall ratio to the building. On the South side the entire building is glazed, this is to promote natural solar gains through the building growing atrium in the winter months. This natural solar gain is controlled by shading devices that grows depending on the solar energy available. These solar shading devices are the reed beds themselves and grow in the growing cycles on the exterior. The north, mere facing side has a series of windows that provide observation to the mere as well as indirect natural light to the internal spaces forming a glazing to wall ratio of 1:4 on the ground floor
Energy considerations
The roof structure is a cross vaulted arch that has a membrane across the tension wire. with a rain water capturing gutter that diverts and captures the precipitate for use within the building.
The building has a mono-crystalline photovoltaic strategy on the South facade of the building. The growing cycles with the integrated PV cells have single axis tracking from east to west to attain optimum energy generation throughout the day. The 6 arrays can generate power to be used within the building, taking a direct current source that is stored in batteries and has the potential to be inverted, and electricity supplied back to the power grid at a profit. The lighting strategy and electricity use within the building will also controlled as to be low as well as natural ventilation further reducing consumption, an anaerobic bio digester is used to capture methane from biological waste produced within the building, this includes waste reed beds. The methane is used in a biogas boiler to heat the building to reduce the energy loads to the overall building.
Fabric membrane composition
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Two ETFE layers are inflated with an air gap between the two membranes, the outer membrane is coated in a super hydrophobic coating that reduces cleaning to a minimum to ensure optimum transparent clarity. The interior layer is also an ETFE polymer, with a UV resistant coating.
Scale 1:100
Material Sourcing LCA The majority of the materials used have to be as reusable as possible for life cycle assessment reasons. A Local steel manufacturing company in cheshire will be used to manufacture the cross vault arches and the structural frame, localized sourcing is used to reduce the carbon footprint on the energy intensive steel manufacturing process. The structural coated Teflon titanium dioxide membrane fabric and the ETFE Instead of a traditional liquid biased gel, Silica aerogels replace liquid fluid with a Gaseous fluid that This new material behaves as a translucent solid super light and thermal insulating material, with an incredible R-value of 11.7, it is a good insulator to sound and the membrane can be impermeable to moisture. These properties give the composite an ideal membrane composition for both thermal and acoustic consideration
membrane fabric can be sourced from specialist fabric construction companies within the UK. The fabrics are then cut using CNC precision. The steel cables used to hold the roof in tension will also be sourced from a locally with companies like Architen landrell technically resolving and manufacturing proposed projects.
Reflection Tectonics this semester has been valuable in both broadening my understanding of structural and material applications to buildings. The beginning lectures on how concrete span structures can be calculated and the formation of concrete itself helped me to develop my understanding of buildings that did not fit my prior knowledge of construction. Examples of this were concrete shell architecture, Oceanografic Valencia where parabolic and hyperbolic forms can form self supporting large open spanned spaces, although the construction of the roofs was a long manual process of Pouring, levelling and polishing to achieve the concrete arch seen in the picture. This fuelled my own research into how these structural shapes could be achieve at a fraction of the material and structural element. I began researching into tensile fabric architecture that twinned tectonically with sell architecture and hypar shapes. These proved easy and simple to construct, in a fraction of the time. Reducing the complexity of both the fabrication and assembly process. Tensile fabric structures requires an initially structural frame to be constructed. The frame would be the a freestanding skeleton to would anchor the fabric membranes spanning across to create a closed envelope. Designing an interesting structural frame with structural arches was key to a good fabric structure as it provided the form work of the fabric membrane shapes. Even my Easter trip to California saw interesting arched construction at both sides. Heathrow Terminal 5 and in Los Angeles LAX Terminal. With the use of arches to achieve large spans creating an enclosed negative space. The lectures on structural glass inspired me to use it in my building. The growing atrium is a structural glass wall with additional support from the buttress. I enjoyed the practical session of making the concrete blocks and the playful aspect of adding alternate materials to the aggregate to achieve alternate concrete and composite materiality. The practical study broadened my understanding of concrete beyond basic steel reinforcement and broad my knowledge of the use of additives to give concrete new properties. If I were to have change one thing about my building, it would have been to have used a more environmentally friendly material in terms of manufacturing the membrane fabric. Teflon as practical as it is requires strong acids and energy to polymerise and form Teflon. The other change I would make is to the Steel frame structure, as steel is not compliantly inert to oxidisation unless alloyed. Reading into glue lam structures proved a lighter and less energy intensive manufacturing process. Glue lam can be formed into arcs that could span the distance of my structure. Doing the Meng Degree gave me a break to then a drive to return into architecture with an engineering consideration. This made me took at structure in a more logical way. I enjoyed how this module tied so well with studio to complement and drive me to better integrate structure and the design side of architecture.
http://en.wikipedia.org/wiki/File:Oceanografic_Valencia.JPG