Classrooms in the Park Group 17 Alice Mellor Ayesha Puri Alex Bull Sebastien Rhone Adam Engstrom
Contents
A building built by the community for the community Introduction History of the Serpentine and Kensington Gardens History of the sites Kensington gardens analysis Concept and brief definition Community precedent Defining the plan Material response Material precedents Model and Concepts
Drawings Floor Plan The building use Community Space Floor Plan Site Plan Site Plan Long Section Short Section North Elevation South Elevation Interior perspectives Exterior Perspective
Analysis Building Environment Analysis Model photos Exploded Isometric Construction Concept Material Justification Structural Solutions Load Paths Environmental Analysis Connection Details Bamboo Calculations Foundations Environmental Considerations Construction Sequence Legacy Prospects Post critic analysis
The Serpentine and Kensington Gardens History and culture
Kensington Gardens and the Serpentine are located in one of the most centrally located parks in London. They are the common persons escape from the busy city life. The Serpentine gallery and the Serpentine Sackler gallery are a popular cultural destination within the city. They commission artists to create artwork for the gallery which is displayed on a typical three month basis. The main event of Kensington Gardens is the Serpentine Pavilion. A new pavilion is designed and built every year. Each year a new architect is asked to design the pavilion, this architect will have no previous experience of building in the UK. The pavilion does not have to contain any particular functions or spaces. The pavilion is in its simplest form an expression of architecture. The park attracts many visitors every year. However, the current Sackler gallery lacks space to accommodate the large amounts of visitors and school groups it receives.
Future Site Strategies A temporary building
Although the building is designed with the context in mind the temporary nature of the building lends itself to becoming site free The current site is located on the border between Kensington Gardens and Hyde Park. The site is located in a close proximity to the Serpentine Gallery The future site will be: Dulwich park, London borough of Southwark - Winter 2015 Richmond Park - Spring 2016 Queen Elizabeth Olympic Park, Stratford - Autumn
Dulwich park, London borough of Southwark - Winter 2015
Richmond Park - Spring 2016
Queen Elizabeth Olympic Park, Stratford - Autumn
Analysis of Context
Kensington Gardens and the Serpentine
Wind
Sunlight and Shadows
Views on Site
Movement of the People
Pauses on Site
Introversion and Extroversion
Concept and Brief Interpretation Education on culture and tradition
Our building is designed as a Cultural Education Centre. The centre will host organised workshops for children aged 5 - 18 of up to groups of 80 people. Workshops will be carried out educating groups about the different cultures around the world and how they differ in their adaptation and approach to the environment they live in. Local artists or lecturers will begin the workshops with a brief talk about the different cultures around the world, the way they live, build, eat and survive. Each group will then begin with the same set of materials, any additional materials they wish to use must be sources from the surrounding parkland and context. Using the items they have been given and any materials the can sustainably source from their environment groups will be asked to build an object or sculpture. Upon completion, groups will be able to exhibition their creations within the building. These exhibition act as inspiration and precedent for future groups. This process of creating something based on the materials you have available in the environment around you to create different results is integral to our Educational Centre. It is one of the most important messages we intend to communicate through our full scheme.
A Classroom Community Community precedent
S達o Paulo Bookshop
2014 Studio MK27, Marcio Kogan Iguatemi, S達o Paulo
Crystal Bridges Museum of American Art
This book store is designed as a community space. Shoppers are encouraged to stay and read in the large open plan. The large steps are also used to host lectures and talks with visiting writers. Although the function of the book shop remains very clear through the scheme, the community aspects of the store is evident in the design. The space is adaptive and multi functional dependant to the current needs of its users. It can act as a simple meeting point or a full on stage dependant on the required function. Move importantly, the space remains in use even after lectures finishes, it does not suffer the same issue as a modern day classroom that repeatedly fills up and empties.
2011 Moshe Safdie Bentonville, Arkansas The large community space achieved under the large span allows for many combinations of community integration.
A Classroom Community Flexible Space
The building plan is generated from the site context. 
The natural clusters of the trees are used to map the clusters in our building
The trees locations are then adjusted to form a functioning plan
The trees mapped onto the plan
Movement of the tree locations
Creating the final plan
Material Response
Architecture are pedagogy
The Serpentine gallery is a celebration of architecture and an exhibition of a new architect with no previous experience of building within the UK. Our building is designed as an exhibition of a material non-typical of the UK - Bamboo. Bamboo is a plentiful and commonly used material in East Asia, India, Himalayas and Africa. Bamboo belongs to the grass species and is one of the fastest growing materials of most sustainable materials in the world. Bamboo has a greater compressive strength than timber and rivals steel in tensile properties. However it is not natively grown in Europe and there are few examples of bamboo being used to its full potential within the UK. Our use of Bamboo in the heart of London is a showcase and an education of the potential bamboo has to be used in the UK. As a cultural education centre, the use of bamboo for the building form as an education in culture itself.
Bamboo Precedent Images An exploration of a material
Kontum Indochine Cafe
Centre Pompidou-Metz
Kindergarten Classroom
Bamboo Pavilion
2011 Vo Trong Nghia Architects Vietnam
2010 Shigeru Ban Architects Metz, France
2008 Green Village Project Sibang Kaja,Bali
2010 Vo Trong Nghia Vietnam Expo
The bamboo is sculpturally adapted and expressed in the building form. The bamboo material forms the structure of the building and is sourced locally giving the building a particularly low carbon footprint.
A hybrid material, a combination of Glulam and Bamboo, is used to create a gridshell structure.
The Green village project showcases the use of Bamboo to create a large span building with minimal central columns. Bamboo is primarily used in compression.
The bamboo structure is clearly expressed. Lighting is used to draw attention to the sculptural forms of the Bamboo. Bamboo is used structural in compression.
Initial Concept Models A developing form
Several test model were made during the design process. Each model, in combination with appropriate precedents, would inform the next model.
Bamboo is rivals steel in its tensile properties, it also has extremely good compressive strengths. This lead us to look into arches and curved shapes.
Although bamboo lends itself to gridshell structures, we ruled it out early due to the temporary nature of the building and the brief.
Looking at the idea of people converging at a centre and diffusing out. A central column concept was developed.
Alternative were explored to achieve more sable floor space without increasing larger spans.
The circular form gave rise to issue dividing the plan into usable spaces so it was removed.
The form of the plan was derived from the site giving a much more site specific building.
The central detail where are the beams were crossed was deemed too intricate for such a project. With a non-circular plan the central column was reintroduced.
This plan was adapted and adjusted to more appropriate fit the needs of the community.
A Building Form
A combination of function and form
Ground Floor Plan 1:100
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Main classroom clusters
A Community Space The building use
Classroom
Social Talks A multi functional space, a formation derived based on its current function
Community amenity
A Community Space
Separation without isolation
The bamboo backing can also be used to create a sense of privacy A transition from a public to a private space
The seating areas are at three set height levels. This provides elements of separation in the building for more private sessions without isolation the group or alienating those entering the building
Site Plan 1:500
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Site Plan
0 5 10 20
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Long Section 1:100
Short Section 1:100
North Elevation 1:100
South Elevation 1:100
Internal Perspective
Internal Perspective
External Perspective
Building Environment Analysis A building in context
Model Photos
Model Photos
Resistant to Water Resistant to UV radiation Very flexible Very lightweight
Bundled bamboo allows for larger spans Poor Resistance to water and UV Very lightweight structure Works in conjunction with PTFE canvas
Series of sunken table areas Tables form community and social spaces Spaces are adaptable to group numbers or ability
Concrete foundations take compressive loads Timber scaffolding supports lowed seating areas Central foundation collects water run off and drains safely into the ground
Concrete foundations to support structural bamboo beams
Foundation Level
Bamboo flooring suspended on timber scaffolding
Ground Floor Level
Bundled Bamboo with Steel Ties
Main Structural Beams
PTFE Material with Silicon Lining
Tensile Structure
Bamboo Arches
A Construction Sequence
The bamboo is bundled into bundles of seven bamboo pieces. The pieces are cut at different lengths and then slot together to form a larger span. The bamboo will be fastened together using steel clasps, shown on the right.
A Structural Solution Material Summary
Bamboo Bundles: Using small pieces of bamboo to create larger piece enables larger spans within the building By bundling the bamboo, we can create deep, stiff yet light members. Friction between the bamboo members adds strength to the bundle while maintaining flexibility. Environmental Ventilation: PTFE is breathable material that allows natural ventilation of the building. PTFE is flexible and extremely durable. Structural The structure consists of 16 arches made of bundled, pre-tensioned bamboo. The arches come in segments that are assembled onsite using large hose-clamp steel ties to facilitate construction and deconstruction. The arch gradients are low, reducing bending moments in the members. The moments are further reduced by having the arches connect to the concrete foundations at an angle. The forces at the foundations are only compression. The structure is covered with a PTFE membrane coated with silicone to provide protection from rainfall and UV radiation. The PTFE to bamboo arch connections make all the arches interconnected providing lateral stability thus making the building a tensile structure.
The raised flooring will arrive onsite in pre-made slabs made up of sheets of plywood with cellulose insulation. The slabs will be propped up on wide-based steel poles that can be adjusted in height to better fit the contours of the site. The entrance to the structure will be glazed with plexiglass which slots into channel frames allowing for thermal expansion of the material. A gap at the top between the arches and glass is left to allow for ventilation of the building. Lighting PTFE diffuses direct sunlight resulting in a well-lit, non-glaring internal environment. Heating: PTFE is connected to floor around edges to make building airtight. Building is heated up by diffused sunlight throughout the day and also the occupants. Flooring is insulated as it is used for seating. Floor has some capacity to retain heat from sunlight and release it through the course of the day. In winter building is oriented so that the entrance is facing south. The low angle of sun will allow direct sunlight to enter the building through the transparent Plexiglass. If additional heating is required, small electric infrared heaters can be used. They are energy efficient as they heat up surfaces instead of a large volume of air.
A detail of the steel clasp. The clasp is easily removed and can be tighten if the bamboo shrinks over time.
Load Path Analysis
The arches are designed so that the angle of the connection at foundation level remains below 45 degrees. This minimises the moments in the foundations and instead increases compressive loads. The foundations are designed to deal with these compressive forces. The PTFE material provides bracing between arch members providing overall stability to the structure. The tensile structure is very efficient with dealing with rain and wind loads as the forces are spread across the structure and down to the foundations.
A Structural Solution
Table build up and structural solution A detail showing the connection of the plexi glass to the bamboo arches. The plexiglass is designed to appear as transparent as possible. This maintains the strongest connection between the inside and outside of the building. The plexi-glass is supported by steel channel sections that slot into the bamboo arches. The plex-glass does not form an air tight seal at the top of the bamboo but instead stop 5mm short.
Table Detail 1:20 1. Floor build up
2. Insulated lower deck 3. Storage Space
This detail is repeated along the bottom of the building.
4. Seating area 5. Bamboo backrest
5 4
4 3 1 2
Connection Details
3
1:10
1. Bamboo bundles 2. Steel Clasps
1 2
3. PTFE and Bamboo connection
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4. PTFE with silicon lining 5. Metal grommet connection with PTFE and cable tie 6. Steel hook connection 7. Steel foundation ring
5 6
8. Concrete foundation
Designed to take compressive strength
9. Steel shoe
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Grips the bundles of bamboo
10. Water Collection
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Water is dispensed by soak-away concealed in the ground
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11. Floor Build Up
2x12.5mm laminated bamboo flooring 75mm mineral wool insulation Joists at 600mm centres 12.5mm plywood
12. Structural support for suspended floor Scaffolding system
8 10
12
Connection Details 1:20 Details
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4
5 5 4 6
3 3
4 2
2 8
8 1
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7
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Detail 1A - Cut through canvas
6. Bundles of Bamboo
Detail 1B - Cut through foundation
1. Ground
7. Scaffolding floor system
1. Concrete foundation
6. Bundled bamboo arches 7. Scaffolding floor system
2. Concrete foundation
8. Floor build up
2. Steel shoe
8. Floor build up
3. PTFE foundation connection
3. PTFE - concrete connection
4. PTFE - floor deck connection
4. PTFE with silicon lining
5. Steel clasp
5. Steel clasps
Bamboo Calculations
Moment Bending in Bamboo Section modulus calculation:
Dimensions of the bamboo: D=100mm d=80mm Ai=πR2-πr2=π(502-402 )=2827mm2 Ilocal=(πR4)/4-(πr4)/4=π/4 (504-404 )=2898119mm4
Load combination: Load cases: Mk,1= 0.325kN/m=Self-weight of the bamboo Mk,2 = 0.088kN/m =Self-weight of the PTFE Mk,3= 2.65kN/m =Wind loading Instantaneous loading: Md=γG (Mk,1+Mk,2 )+γQ (Mk,3 ψq,3 ) γG=1.35 γQ=1.5 ψq,3=0.5 MD=1.35(0.325+0.28)+1.5(0.5×2.65)=2.8kN/m VA=VB=(2.8×19)/2=26.6kN Moments about mid-span=2.8×9.5×4.5=119kNm 26.6×9.5=HA×4.8+2.8×9.5×4.5 HA=27.8kN The thrust into the ground, is the sum of these two forces, therefore, F=√(27.82+26.62 )=38.8kN
I=(3Ilocal )+2×(2Ilocal+2Ai×100)=8694357+2×6361638=21417633mm4 Z=I/ymax =21417633/150=142784mm3 Maximum moment calculation PTFE weight calculation: ρPTFE=2.17g/cm3=2.17×103kg/m3 Weight of PTFE=ρPTFE×g=2.17×103×10=21.7kN/m3 Thickness of the PTFE=3mm Width of the PTFE acting on a single bamboo pole =5m Weight of PTFE=21.7×0.003×5=0.325kN/m Bamboo weight calculation ρbamboo=0.33×103 kg/ m3 Abamboo=1502×π=0.0707m2 Self weight of the bamboo=ρbamboo×7Abamboo g=330×0.0707×g×23=5.366kN self weight of bamboo acting as UDL=5.366kN/19m=0.28kN/m Wind load calculation wind load=0.53kN/m2 5m of canvas per arch, therefore, wind load=0.53×5=2.65kN/m
The maximum moment in the arch will occur at quarter-span. M1/4=2.8×4.25×2.4+119+27.8×2.4-26.6×4.75=87.9kNm Stress at quarter span: σ=M/Z=87.9.106/142784=616 N/mm2 Bamboo modulus of elasticity in bending is 11800N/mm2, therefore the structure is safe.
Foundations
Sizing of Foundations
To verify the foundation’s ability to carry the structure, we will calculate if it can do so while soil.
sitting on top of the
Assumptions about the soil: Since we don’t know much about the soil, but a borehole log from the Princess Diana Memorial Fountain shows the top layer of the soil is made ground for 5m, we assume a weak, undrained soil, poorly compacted. Therefore, we can make the following assumptions: θ’=0° γ=15kN/m^3 Cu=20kN/m^2 Size of the foundation: H=700mm B=500mm A=0.25m2
W=500mm
Bearing capacity factors The soil is undrained, therefore, we can assume the friction angle θ is 0, therefore, the bearing capacity factors are: Nc=5.14 Nq=1 Nγ=0 Inclination factors The load will be inclined, therefore, there will be inclination factors: ic=0.5+0.5√(1-H/(A Cu ))=0.5+0.5√(1-0.7/(0.25×20))=0.96 iq=1 iγ=1
Shape factors The foundation had a square plan section, therefore the shape factors are as: sγc=1+Nq/Nc =1+1/5.14=1.2 sq=1+tanθ’=1 sγ=0.6 Soil bearing capacity: q=0,so qNq sq bq iq=0 Nγ=0,so BγNγ sγ bγ iγ=0 R/A=20*5.14*1.2*0.96+0+0=118kN/m2 Design horizontal load: 26.6KN Rd=83×0.25=29.5kN 29.5kN>26.6kN therefore the foundation is safe Since the foundation is safe to carry the arch while sitting on the ground, it will be able to hold the structure if it is put into the ground.
Environmental Considerations A sustainable building approach
U-value calculations U-value shows how good a part of the building is at retaining heat. Rse=0.13 Rsi=0.04 λtimber=0.13 λinsulation=0.04 R=L/λ Rtimber=0.013/0.13=0.104 m2K/W Rinsulation=0.075/0.04=1.875 m2K/W Rt=0.13+0.104+1.875+0.104+0.04=2.253m2K/W U=1/R=1/2.253=0.44 W/m2K This value is relatively high, but as we have explained, the building will provide shelter and a place to do things with materials found outdoors, and will not retain a lot of heat. Ventilation through the building
Daylight factor: The daylight factor is the percentage of daylight that passes throughout the building envelope. Df,mean=θ/2 aw T/(ar (1-ρ) ) aw=area of the PTFE membrane = 454m2 ar= floor area =327m2 T=transmittance of the PTFE membrane =15% ρ= reflectance of the bamboo matting =31.8% θ=angle of sunlight on the roofing =120° Df,mean=120/2×454×0.15/(327(1-0.318))=18% This is a very high value, since the roof is in essence a large window. We will therefore not need artificial lighting.
Circulation through the structure
Environmental Considerations A sustainable building approach
Location and Orientation on Site The building is by nature a very lightweight structure. The main thermal mass comes from the insulation in the floor.
Heat Entering the Building
The building is orientated on the site to gain the most heat from the sun during the day. It will heat up quickly in the morning and cool quickly in the evening. This is ideal for the set hours the building is in use. 10am - 8pm The building is orientated with the main entrance facing away from the strongest South-Western winds. The structure will not provide the same environmental atmosphere as a typically insulated house; instead it provides shelter from the rain and wind as well as residual heat from the other user of the building.
Heat Convection
Wind Loading
The Assembly of Structure
The essence of a temporary building Our concept focuses on the idea of community, the involvement of the local people in the construction of the building represents. The bamboo arches designed in such a way in that each individual member could be carried by two people. The entire arch could also be lofted by hand. The building can constructed by hand, using traditional build technique The building will be built be the community, for the community about the education of culture and tradition.
Construction
Excavation Earth will be excavated for flooring area, locations of PCC foundations, and external landscaped area. An excavator and a truck will be required to remove excess soil from site. Some of the excess soil will be used to build up the ground level at the entrance of the building and to create slight gradients using the existing contour slopes for external seating areas.
Construction
Foundations Precast concrete foundations will be brought to site and put in place using a mobile crane. Because the foundation of each bamboo arch differs slightly (due to the angle at which each arch hits the ground), they will need to be systematically organized before arriving onsite, to speed up positioning.
Construction
Floor substructure and structural deck Adjustable columns will be set out on excavated earth, based on the heights required to build the floor level. A prefabricated timber structural deck will then be laid upon these columns to create a level surface for the floor to be built from. This deck will be divided into transportable pieces and carried to site by hand.
Construction
Arches The bamboo arches will arrive on site pre bent. They will be bundled together in transportable pieces, with the final bundling taking place whilst on site. Two sections of an arch will be strapped together with an adjustable steel strap for structural support. The straps will be adjustable to accommodate the shrinking of the bamboo over time. During construction of the remaining arches, temporary bracing will be provided to those already standing. The bamboo will then be slotted into the steel shoe foundation connection by hand to secure the arch.
Construction
Canvas The PTFE canvas will be prefabricated into sections and then sown together with weatherproof seams. In addition, they will be attached to the bamboo arches themselves with fabric ties. Once the PTFE is laid and tensioned, it will provide bracing to the arches, and the temporary bracing for the arches can then be removed. Removing the bracing after the PTFE is attached, ensures stability, and prevents any potential structural hazards to the people constructing it.
Construction
Installation of raised flooring with seated areas The raised flooring will be insulated throughout to provide a barrier from the ventilated floor below. The floor will be prefabricated in transportable sections, and the seams of it will be hidden by a bamboo mat laid on top.
Construction
Plexiglass The plexiglass will form the final weatherproof barrier and seal the building, whilst remaining lightweight to carry. The glass is held together by steel channels concealed within bamboo sections on either side, and similar ground channels for stability. By leaving a 50 millimeter gap between the panels of plexiglass at both entrances, we aim to encourage a constant flow of ventilation throughout the structure.
Construction
An overall view of the completed structure. Deconstruction 1. Removal of glass and frames. 2. Removal of furniture. 3. Matting laid out for tower crane to de-attach canvas. Canvas then removed. 4. Arches lifted out by crane after release of foundation connection. Arches disassembled on ground and put into container. 5. Removal of flooring. Done in a sweeping motion i.e. floor, joists and supports all taken out at the same time starting from one end of site. 6. Foundations lifted out. 7. Excavators brought in to level the ground.
Legacy
What is left behind The legacy of what we leave behind An extension of our internal spatial layout included excavating shallow pods along the grass, around the existing desire lines on site. These pods are a reflection of the central concept of our design, in the way in which they form clusters to bring together groups of people, with the aim of creating a sense of community. By leaving them behind as a legacy of what we created, we aim to illustrate the integration of our built environment with the surrounding landscape, in a way that engages the community to feel at harmony with their natural surroundings. The basis of our building form began with the idea of a central point around which a community interacts. Hence, we also chose to leave behind the central concrete foundation that would have growing bamboo in place of where the original bamboo members met in the centre. We hope for this to carry our idea of encouraging bamboo construction in and around the UK forward, and to remain a symbol of everything our structure represents in terms of sustainability, nature and community.
Prospects
What there is to look forward to
Dulwich park, London borough of Southwark - Winter 2015 Richmond Park - Spring 2016
Queen Elizabeth Olympic Park, Stratford - Autumn 2016
The temporary nature of the brief pushes toward a building that is context free. Although the context may change, the involvement with the community and the site will not.
Post Crit Analysis A self evaluation
Following our meeting with the critics, we were advised to better resolve certain structural aspects of our building which we hadn’t fully conveyed diagrammatically in the crit. The critics wanted to gain further insight regarding the way in which the PTFE material is attached to the floor structure to create a seemingly air tight envelope. They were also curious about how the different levels of the floor seating would work, and how they would be built into the structure. We therefore, worked out a way in which the PTFE ties to the floor structure, and represented this diagrammatically. We also resolved the flooring details to illustrate how the different seating levels would actually be constructed and used. Further to this, the critics felt that our foundations seemed overengineered in comparison to the simplicity of our overall structure and the concept of our design. We therefore looked into the potential of using a Gabion foundation detail which could be made out of natural materials such as locally sourced stone. We have also tried to simplify our construction method even further, by exploring the possibility of steel pivots between the bamboo and the foundation where the people could actually construct the arches on the ground before hoisting them into their vertical position.
The use of Bamboo in the UK is not as far off as we may think. With care and thought, elegant bamboo buildings can be built. If this scheme were to be built, the bamboo could be planted and grown for construction in just 4 years.