1 Technical University of Cluj-Napoca, Faculty of Architecture and Urbanism, 34-36 Observatorului Str., 400500, Cluj-Napoca, Romania Received 12 May 2011; Accepted 20 August 2011 Structure has a manifold role in architecture. First is that of stability and strength, then is the role of sustaining the architectural aesthetic concept on the level of the facades; another important role is regarding the quality of the interior space, through the capacity to give a rhythm, to distribute, to liberate and to offer a maximum of flexibility to the configuration of the interior space and also to allow for a good relationship with the natural light, on the level of the covering. The natural light is tapped into the interior space of the buildings through hollows in the facades: windows, panoramic openings of different types, skylights, etc. Among the other factors that control the level of comfort of a building (heat, air, sound and water), natural lighting has a big contribution to the quality of built space, its contribution depending on the purpose of the building, the spacial typology, the surface and the complexity of the functional scheme. The structure of the building supports the opening system of the facade, it optimizes the distribution of natural lighting in the architectural space and it contributes to the helioplastic effects in the ambiance of the architectural space. Rolul structurii în arhitectura actuală este multiplu. În primul rând este acela de a oferi stabilitate şi rezistenţă, apoi are rolul de a sustine conceptul arhitectural estetic la nivelul faţadelor, un alt rol important îl are în calitatea spaţiului interior, prin capacitatea de a ritma, distribui, elibera şi oferi maximă flexibilitate configuraţiei spaţiului interior şi de asemenea de a permite la nivelul anvelopei o bună relaţie cu lumina naturală. Lumina naturală este captată în spaţiul interior al clădirilor prin intermediul golurilor faţadelor: ferestre, deschideri panoramice de diferite tipuri, luminatoare, etc. Pe langă ceilalţi factori care controleaza gradul de confort al unei clădiri (căldura, aerul, zgomotul şi apa), lumina naturală are un aport foarte mare în calitatea spaţiului construit, aportul acesteia fiind necesar în mod diferit în funcţie de destinaţia clădirii, tipologia spaţială, suprafaţa şi complexitatea schemei functionale. Structura construcţiei susţine sistemul de deschidere la nivelul faţadei, optimizează distribuţia luminii naturale în spaţiul arhitectural şi contribuie la efectele helioplastice în ambianţa spaţiului arhitectural.

Table nr. 1. Average heights for different postures.

Dana Opincariu / Acta Technica Napocensis: Civil Engineering & Architecture Vol. 54 No.1 (2011 ) 82-92 1. Sealant, 3 mm polyurethane coating Leveling layer, 10 mm mortar 200 mm reinforced concrete slab 20 mm insulating mortar 3 mm coating 2. 5 mm stainless-steel sheet 3. Glazing, 19 mm, toughened glass 4. Integrated drainage: Ø 216 mm steel tube 5. 20 mm marble 10 mm mortar bed 20 mm thermal insulation 200 mm reinforced concrete 6. Condensation channel, stainless-steel 7. 165/12 mm steel flat 8. 165/9 mm steel flat Figure 2a. Municipal Funeral Hall, Kakamigahara, Japan, Toyo Ito & Associates 1. Primary loadbearing framework of steel circular hollow sections, 140 mm dia., welded nodes, painted white 2. Horizontal bracing, steel circular hollow sections, 140 mm dia., painted white 3. Stepped insulation glass, 10 mm toughened safety glass + cavity + 2 No. 8 mm laminated safety glass, projecting outer pane bonded to aluminium frame 4. Specially formed framing member 5. Inspection opening for district heating duct 6. Silicone seal Figure 2b. Faculty of Law, Cambridge, U.K., Sir Norman Foster and Partners, 1995 85

Table 2. Factors that influence the daylight penetration according to the window geometry (fig. 2c).

Dana Opincariu / Acta Technica Napocensis: Civil Engineering & Architecture Vol. 54 No.1 (2011 ) 82-92 and its organization on various levels, but also because this kind of a building means an adequate configuration of the structural system, of the layout, a building that means high conditions of design and construction, much more complex than those of the regular type of buildings. The same basic principles of structural design apply to high rise buildings as for any other type of construction (fig. 5). Individual members and the overall structure must be designed for adequate strength under gravity and lateral loads and there needs to be enough stiffness built into the structure to restrict deflections to acceptable levels7. Figure 5. Structural systems for high-rise buildings. The shape of level layouts of these high-rise buildings has to avoid open, asymmetrical shapes such as L, T, X, C or Z. The layout of these high-rise buildings has to be configured in symmetrical, compact, circular, square or triangular typologies. High-rise structures can be divided in two categories, according to the placement of the structural system: interior structures and exterior structures. Interior structures are high-rise structures that resist lateral loads primarily through lateral force-resisting elements located within the interior of the structure, such as rigid steel or concrete frame structure or a structure braced by a core consisting of braced frames, moment frames, or shear walls constructed into a closed system that acts as structural tube. Exterior structures are high-rise structures that resist lateral loads primarily through lateral force resisting elements located along the perimeter of the structure8. (fig. 6) Figure 6. Commerzbank Headquarters, Frankfurt, Germany, Foster & Partners, 1997 90

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