Alvaro Siza
Viana do Castelo Library claire shafer
Alvaro Siza
Born in 1933 in Porto, Portugal, Álvaro Siza has become one of Portugal’s most renowned architects. He attended the School of Architecture at University of Porto, where he quickly started his own practice in 1954. Throughout his acclaimed career he has taught at his Alma mater starting in 1966 and has been a visiting professor at many graduate architecture schools such as GSD at Harvard University, University of Pennsylvania, and Los Andes in Bogota, Colombia. Siza has received many awards, including Pritzker Prize for architecture in 1992, European Architectural Award from the Mies van der Rohe Foundation in 1988, for his lifetime of achievements and for individual works.1
Viana do Castelo Library
Viana do Castelo , portugal program/Public Library design/2000-2 construction/2002-6 Structural Engineer/GOP Built area/1605M2 TOTAL floor/3077M2 2
SITE PLAN
n
The library {in gray} was part of the master urban plan by Fernard Távora for the river banks of the Lima River in Viana do Castelo. The building is positioned parallel to the river and takes into consideration the sun path for window placement and solar shading.3
Conceptual Design
The conceptual design for the library was to continue the view to the river from the street and the surrounding areas as much as possible and to complement the other buildings in the urban plan. Siza achieved these goals by elevating the main mass to create a continuous landscape to the river and by the horizontality of the building acknowledging the surroundings.4
FLOOR PLANS
Siza carries the orthogonality through the massing, the plans, and the elevations. The first floor raised volume is 45 meters by 45 meters with a 20 meters by 20 meters void in the middle that looks over the public space below. The program is divided so the entrance, staff areas, and conference rooms are on the ground floor and the main reading areas are on the first floor.5
Eleva tions
The elevations of the building continue the orthagonal lines from the plan to compose two shifted volumes with a low profile to anchor the building to the surrounding landscape. This horizontality is continued through the size and location of the windows and the wall that surrounds the gardens.6
Sec tions
The engineering feats are best displayed in section because the long spans of concrete are more visible in the elevated volume.
STRUCTURAL DESIGN
Two Areas Area 2 The building is structurally divided into two different areas. Area 1 is composed of typical reinforced concrete wall with steel and concrete composite slabs, and “is continually laid at the level of {the ground floor} on the foundation. Area 2 is more complex because of the elevated volume that has lengths of concrete on the underside of the volume with no vertical support. The volume is supported because it ”rests on the first {level} and on two L-shaped supports.”7
L-Shaped Supports
Area 1
Area Two
The elevated volume of Area 2 required extreme precision in the design and engineering of the structural system in order for the concrete not to crack because of the deflection in the long spans. To reduce deflection, Area 2 “is composed of structural steel framing coated with reinforced concrete.”8
20m x 20m Void
Framing System Steel Frame Section
L-Support
Pre Fabricated The steel framing system was prefabricated in pieces so the quality of construction could be higher to reduce extra stress caused by weak connections made on site. Therefore, screw {shear} connections were used {see below} to assemble the pre-fabricated steel frame sections.9
Steel frame in workshop
Screw connections on site
L-Shaped Supports The L-Shaped supports are the key to keeping the Area 2 volume elevated. The steel framing on the interior has a Y shaped elevation to concentrate the load down to one point and then the steel Y is supported laterally by reinforced concrete walls {as seen in the section}. This shape also allows the edge to be cantilevered. This angled “column” is the most efficient design to support this cantilever.
Concrete SteeL The combination of concrete and steel allowed the architect to execute his concept of continuing the view to the river. This combination is achieved through prestressing both the steel and the concrete. The concrete slab’s draped tendons can be seen in the sectional view. The steel frame has stirrups and reinforcing surrounding it so that the concrete can be directly applied. 10
Draped tendons
Pre-stressing detail
Foot notes 1 http://www.pritzkerprize.com/siza.htm 2 GA Document, 80-1. 3 GA Document, 81-2. 4 GA Document, 81. 5 GA Document, 81. 6 GA Document, 81. 7 Sobreira, 5. 8 Sobreira, 5. 9 Sobreira, 7. 10 Sobreira, 10.
Biblio graphy “Alvaro Siza: Viana do Castelo Library.” GA Document 91 (2006): 80-83 “Alvaro Siza: Biblioteca Municipale.” Casabella 66.700 (2002): 53 Editorial Blau, Lda. “Álvaro Siza Viera” 30 July, 2008. Pritzker Architecture Prize Website, “Alvaro Siza: Pritzker Architecture Prize Laureate 1992.” 30 July, 2008. Sobreira, Joao Maria. “Structures and Infrastructures: G.O.P.” The Portuguese Steelwork Association. 20 July 2008 . Images: 21-30 July 2008.
