2014 SRA has revamped this lecture to drop all of Maillart buildings except the cement hall and try to introduce a better treatment of Dieste. Limited success to be honest, but a start, and Maillarts warehouses and the Chiasso roof were never that great anyway. SRA needs to tighten up the notes and image citations.
Most Dieste stuff from the Stanford Anderson Book. compiled by UMass student Ignacio Cetrangolo
15-02 schwandbach bridge and endless ribbon_150dpi.jpg
Maillart showed his playfullness at Schwandbach, but we cannot forget that this form came not only from playfullness but from discipline in understanding the structural behavior
The artist Max Bill, in his biography of Maillart, compares Schw. With the endless ribbon sculpture (mobius strip –see BMA!) shown at top here.
We note particularly the curvature in multiple directions which is occurring here
today we will see, as a followup to roof vaults and national styles, how a sense of playfullness in form can lead to structural art
image from Swiss Legacy bookIsler showing thickness of shellhttp://en.structurae.de/persons/data/index.cfm?id=d000017
And the second, in the Swiss tradition, Heinz Isler
They would each work in the form of the thin shell, but with different materials and different form-finding techniques.
Dieste (left) in brick with roughly mathematical forms
Isler (right) in reinforced concrete with experimentally determined forms
15-05 kresge auditorium_150dpi.jpg
A theme is ‘discipline and play’ and we studied Kresge to understand what happens when you have lots of play without the discipline (constraints) of structural engineering
All play and no discipline
And the result can be buildings which contrast sharply with the dull and heavy constructions which come from a more dogmatic approach to architecture. Instead of thinking about forces the architect here thinks about mathematical geometry the result, unpleasing, and structurally problematic.
http://faultytowers.net/wp-content/uploads/2013/04/Sydney_opera_house.jpg
The same could be said of the Sydney Opera house
Dieste would study in the Faculty of Engineering at the Univ. of the Republic in Montevideo.
He graduated 7 years later. IN Uruguay, the university degree is certification/license to engineer. This contrasts with USA where we must apprentice and take additional tests.
Photo at right is of the main engineering building at the university
1944 he began design work for the Uruguayan Highway Administration. He eventually became head of the technical section of the architecture office (there is something in that implied hierarchy) and at the same time taught engineering at the university.
Evidence of a combination of practical and academic concerns.
1956 founds the firm of Dieste y Montanez with fellow graduate Eugenio Montanez. The firm did design and construction and continues to thrive
Dieste’s material is prestressed brick shown here in a few forms
like reinforced concrete except brick/mortar takes the compression loads. A very cheap material. No/little formwork needed. very low tensile strength even compared to concrete. Prestressing can take care of this
Steel very expensive in South America.
Upper left show’s an example of the Dieste system in which the steel is in the mortar beds between brick layers
Dieste does his best not to rely on hydraulic jacks and makes his system relatively simple to execute
At the crown of a vault: wire loops are placed on top of the hardened brick before the final layer of concrete mortar. The end of these loops were attached to steel reinforcement built into the walls. Between the anchorage ends, the wires are free to move, Prestressed force is applied by pinching the loops at the midpoint as shown in the photo. To do this, Dieste designed a manually operated screw jack. It should be noted that the degree of prestress is determined by the distance between the two sides of the steel loop at its midpoint, therefore the dimensions of the loop are critical.
This method has advantages over conventional ways: the
large radii of the loops allow an even distribution of prestress across the valut and eliminates expensive anchorages. There is less loss of prestress due to mechanical slip and locking off. The equipment is very simple and can apply stress to a group of wires of different lengths at the same time. There is a simple relationship[ between the width and length of the loop, therefore the required extension of the wire can be easily checked.
A social component for the use of Brick
http://en.wikipedia.org/wiki/File:World_gdp_per_country_2012.png
http://research.stlouisfed.org/fred2/series/RGDPCHUYA625NUPN and similar links from ST. Louis Fed
The point here is not that Uruguay is a poor country, in fact it currently ranks 61 in world GDP per capita ahead of most of its south american neighbors
Rather, it is less wealthy than Europe and North America, and in countries with lower GDP per capita labor is often cheaper than materials, making brickwork more economical
And again a social aspect
http://books.google.com/books?id=jK4QyY4vIHgC&pg=PA67&lpg=PA67&dq=dieste+poor+deserve+beauty&source=bl&ots=kh5n4t-Bjc&sig=HOHMnJ4gF8dDCIe9ZN6l4Ko-39Q&hl=en&sa=X&ei=AOtFU-jfNoHlyAGK5IHIDA&ved=0CCkQ6AEwAA#v=onepage&q=dieste%20poor%20deserve%20beauty&f=false
from The Engineers Contribution to Contemporary Architecture by Remo Pedreschi
The ‘deserve’ quote is from Dieste, the other is the sentiment of the donor of the money for the church in Atlantida. About which more later.
within the material of prestressed brick Dieste made four basic forms
The ruled and Gaussian forms are basically mathematical
We will not look carefully at his ruled surfaces
He used graphic statics extensively
Double curvature vaults spanning approximately 150 feet. This is a very long span and also consists of a low rise which is susceptible to buckling. The S shaped transverse bands gives it strength and increases the moment of inertia with minimal increase in weight. In addition, natural lighting is used immensely in the entire span.
Called Gaussian because the shape is that of the Gaussian distribution. Not totally structurally rational
Another view of the plant.
A utilitarian structure
The photo shows the steel tie rods that contain the thrusts of the vaults when you have more or less vertical side walls
Calc sheet (Ignacio Cetrangolo, UMass student) showing what rectangular section would be required to produce the same bending EI stiffness
But the rectangular section also has greater dead load. What if we try to get the same midspan deflection?
An even greater thickness
So Dieste increases stiffness and decreases dead load
Note particularly the single column at the middle. Impossible without prestressing
These self‐carrying vaults are supported by a single row of columns. They span cantilevers of 40 feet each way. This design abled Dieste to avoid using side walls, buttressing, gable walls, and ties. The key to this was the edge beam because it was able to resist lateral forces. He also did this to seek a more gradual and spatial termination of the span in consideration of the people that pass under it.
So much to say here!
Curvature of roof and walls to provide stiffness and buttressing. Very thin for brick.
A story of the design from The Engineer’s Contribution to Contemporary Architecture by Remo Pedreschi:
-Alberto Giudice wants to give a church to the small town of Atlantida-6 years of discussion ensued-Giudice wanted simple, low cost-Dieste argued that the poor deserved beauty (without extravagant expense but without the bare bones box of the ‘low bid’)
-Dieste encouraged Giudice to appoint an architect, but Giudice refused, thinking that he would get something bare bones if he had only an engineer working on it-Giudice argued that the poor had no aesthetic sensitivity-Dieste believed that modest people were sensitive to beauty-Dieste got the project going by promising to build the church for the same cost as a ‘warehouse’ provided he could make the design himself, without an architect.
This was Dieste’s first architectural work. The lighting that is seen in the photos is all natural and it is something that is seen in all of Dieste’s works. It is key in this particular project because it’s a church and it is known what symbolism light is in religion, particularly in Christianity. Eladio Dieste was able to combine the architectural and structural aspects here successfully. The double‐curvature vaults contain tire‐rods that are concealed in the troughs that are anchored in the brick edge‐beam parts beyond the walls. The undulating vaults are self‐stabilizing and are held up by yet again undulating walls that rise to the maximum amplitude of the arcs. Both the walls and vaults meet precisely in a level plane, achieving stunning simplicity.
15-42 cement hall construction_150dpi.jpg
A brief aside for a significant building structure of Robert Maillart
Another new form was the cement hall he constructed for an exhibition in Zurich
He displays dramatically the thinnness possible in a shell of RC
from Gideon’s bookat least one author has claimed that the diagram was the inspiration of McDonalds golden arches.Actually there was originally only one (golden arch that is)
15-45 cement hall construction_150dpi.jpg
This is in opposition to the relatively simple formwork constructed at Zurich
15-48 gotheanum_150dpi.jpg
At right is a brutalist concrete concert hall in Basel
the forms in basel - There is architectural play here, but not structural
15-47 gotheanum_150dpi.jpg
The massive conrete forms in basel versus the thinnes inherent in the Zurich hall
15-47 gotheanum_150dpi.jpg
The massive conrete forms in basel versus the thinnes inherent in the Zurich hall
15-50 cement hall test_150dpi.jpg
Maillart;s form on the other hand was conceived to embody thinness, elegance and strength, as was born out in a load test during the planned demolition of the structure.
The crew was unable to bring it down and had to call in that
15-51 cement hall destroyed_150dpi.jpg
Swiss military that we heard so much about the other day to take it down.
“the eggshell had become an elephant”
Maillart observed the test (coat in left foreground I believe:BWS) and surveyed the ruins just weeks before his own death in 1940
15-52 cement hall at night_150dpi.jpg
The cement hall exerted a strong pull on other designers because of its grace and elegance
image from Swiss Legacy bookIsler showing thickness of shellhttp://en.structurae.de/persons/data/index.cfm?id=d000017
And the second, in the Swiss tradition, Heinz Isler
15-04 british petroleum shell_150dpi.jpg
But discipline and play can also lead to new forms for buildings such as this by Isler, one of our topics for today
A gas station roof!!!!! Just like Dieste
new image from current Princeton version (replaces 15-56 pierre lardy_150dpi.jpg)Pierre Lardy, Prof at ETH Zurich
set up structural models lab, influenced ny model work of Torroja
who had, like Menn, studied with Lardy at Zurich
15-57 isler lab_150dpi.jpg
Isler was greatly impressed by Torroja’s model laboratory in which Isler worked for Lardy, and Isler would go on to develop his own laboratory
Here he would perform very precise structural tests using strain gage and deflection meters
He did not design by these precise experiments, but rather confirmed the validity of the forms he found by other means
Scientific problem that Isler is trying to solve = double curved thin shell on square (or rectangular plan)Same problem as Dischinger and the Germans
one of his first pneumatic shellsnote plastic skylight dome (Isler patent)still has concrete frame at edge
15-59 eschmann shell_150dpi.jpg
Defined by placing a rubber sheet over a square opening and inflating it into a pillow like form
Such a form will be in pure tension for an outward pressure load, and in pure compression for an inward pressure load
The gravity loads on a flat shell are quite close to downward pressure loads (particularly for small curvature)
These are roof analogues to Maillarts flate plate floor structures
15-60 heinz isler with arch forms_150dpi.jpgleft photo=from current Princeton version
Isler examining roof for cracks, esp at corners edges where there is a lot of curvature
But the form was not enough.
Isler had designed an efficient form, but it still had to be built economically
The construction begins with a series of initially very expensive laminated arches
These can be reused and are made possible by relatively inexpensive labor
15-61 shell scaffolding_150dpi.jpg
The arches form the ribbing for the formwork, and light planking spans them to hold the concrete
15-62 fiberboard forms_150dpi.jpg
Next comes some insulation, which seals the form work and stays with the structure
Isler cites Candela’s Xochimilco as a strong influenceand seeks a way to express the thinness of his own free form shells
http://en.structurae.de/structures/data/index.cfm?ID=s0000297notice method of edge stiffeninga la Torroja’s Algeciras Market Hall
15-65 hanging burlap_150dpi.jpg1955
Isler was inspired to his new experiments in form finding by observation of some wet burlap draped over rebar at a construction site
tries same form with thin sheet sprayed with water (4mx4m, 1mm thick)
inverted and still self-supporting
15-66 hanging membrane model_150dpi.jpg
From that observation fo hanging membranes, which can carry only tension loads, Isler got the idea to hang cloth from support points and coat it with liquid plaster or plastic
15-67 hanging membrane model_150dpi.jpg
The suspended form is in pure tension, and, once the plaster hardens
15-68 membrane model reversed_150dpi.jpg
And the membrane is flipped upside down, you have a shell which will be in pure compression under gravity loads
15-68 membrane model reversed_150dpi.jpg
And the membrane is flipped upside down, you have a shell which will be in pure compression under gravity loads
15-64 sicli shell_150dpi.jpghttp://en.structurae.de/structures/data/index.cfm?ID=s0000158
Using this idea, Isler can create very complicated forms which will be in pure compression everywhere.
Here again is the Sicli building, which is supported on seven irregularly arranged supports, and has cutouts as well.
No mathematical theory could have prescribed a compressive form for this set of design constraints
15-63 sicli shell interior_150dpi.jpg
Here is the appearance of the insulation from the interior
Because the concrete is everywhere in compression no cracks can open and not even any roofing material is needed.
slides from current Princeton versionleft = DPB inspecting surface at support for cracksright = prestressing to capture horizontal thrust at edge
slides from current Princeton versionleft = DPB inspecting surface at support for cracksright = Isler on roof
15-73 heimberg shell_150dpi.jpghttp://en.structurae.de/structures/data/index.cfm?ID=s0030518
One his other forms is designed for covering large indoor spaces, such as this tennis center in Heimberg
Here four structurally independent shells are strung together to provide the necessary structure
And again the doubly curving surfaces are reminiscnent of the
‐Closer view‐About 160’ x 50’ ‐About 3” thick‐Dense but light reinforcement‐No ribs ‐“rib” in middle is formed naturally by hanging form ‐Under pure compression no waterproofing
15-75 heimberg shell_150dpi.jpg
Isler creates unprecedented forms which are both natural in form finding and artificial in that they are very human creations which are not based of forms foung in nature
15-76 heinz isler on heimberg shell roof_150dpi.jpg
Isler stands on the roof at Heimberg, where we see the structural discontinuity, and points to the future of thin shell concrete construction
15-77 heimberg swimming pool roof_150dpi.jpgOne of which is the neaby swimming pool in Heimberg
With the mountains of the bernese Oberland in the background
15-69 isler office_150dpi.jpg
Isler is an incredibly playful strutural artist who likes the idea that his approach uses the forces of nature to determine the form
15-70 isler office_150dpi.jpg
His office building is designed so that the top surface of the concrete is always in compression so that no cracks can open
No cracking means perfect water roofing, and so he flooded it and let nature take hold, creating an early version of a green roof.
from swiss legacy book (replaces 15-72 ice tent_150dpi.jpg)
Isler’s playfullness also shows through in his experiments during the swiss winter
Where he coats membranes with water, which then freezes into beatiful thin ice shells
‐Menn and Isler in the “uniform of the structural artist”‐Talking about their teacher, Lardy, who stimulated both of them to create great works of structural art in the 20th c.