Banco Bilbao e Biskaia, Álvaro Siza com Ramón Losada, Bilbao, Spain, 2005
Located in Bilbao, next to the lot designed by architect Moneo, the equipement building has as main function to support all activities related to the university public in the Basque Country. The building, with a gross floor area of 10000m2, it haves a buried ground floor for parking and technical spaces, a ground floor with an auditorium for about 445 people, and for upper floors with several rooms that allow versatility in the use f the space.pppp From the standpoint of implementation, the higher stories/plants present an L configuration with their arms open to the river (positioned parallel and perpendicular to the river). The buried and ground floors have no regular properly form.
Given the proximity to the river, the soil, at the surface of the land has heterogeneous landfills with variable thickness. Bellow this layer there is aluvial material which condition digging and containment solutions. The water table approximately coincides with the transition from landfills, and therefore it is necessary to decrease adopting adequate drainage systems. The excavation was made on slopes with a provisional pending 3H/1V. For the dimensioning of the cutting was considered a resistance to compression 250 Kp/cm2.
As to the vertical structural elements, in general, has been proposed a solution of reinforced concrete walls supporting slabs, bi and unidirectional.
For the façade walls of the building it was proposed 30cm of thickness. Note that same of these walls, in addition to having substantial openings, represent important consoles, and therefore conditioned the proposal for other transverse walls with less thickness to act as their support. These walls in turn provide support:
-To two-way slabs with thickness ranging between 0:20 and 0.30m;
-To Unidirectional composite slabs, when the spans reach considerable sizePPPPP Given the high volume of excavation (5.50m deep) and geotechnical characteristics it was necessary to have containing solutions: -the North facades (parallel to the Abandoibarra Avenue) and a west part, a countention by cuttings shirts recoverable molded withdiameter of 0.85m, for every 5.0 meters;
-in other fronts, through a peripheral containment curtain poles with a diameter of 0.65m, 0.85m apart each In both cases the cutting depth reached, after reaching the desired excavation dimension of twice its diameter.
It was proposed for the foundations a ground floor slab supported on piles with 50cm with their corresponding solid header, with diameters varying from 0.65m, 0.85m and 1.25m and 1.25m.