The Knowledge Level in existing buildings assessment

In this paper a relevant topic in the new Italian Seismic Code is discussed: the knowledge level definition for existing buildings assessment. In the moment in which in a seismic Nation, as Italy in 2003, the Code modifies seismic zoning or it introduces new and more accurate methods for structural analysis, the topic of seismic safety evaluation for existing buildings assumes a relevant role. Particularly in the case of a strategic building that has to be sure during earthquake (avoiding severe structural damage) and to be efficient immediately after the seismic event (avoiding component damage). For these reasons the assessment of an existing building has to be preceded by a phase in which performance objectives, seismic hazard and determination of deficiencies has to be taken into account. Obviously first phases are pertaining to Codes while the latter is devoted to structural engineer. For this aim Code introduces knowledge level as crucial aspect able to define design coefficients and assessment strategies. The aspects that define the levels of knowledge are: global geometry, geometric characteristics of structural elements, structural details, reinforcement ratio and arrangements (in RC structures), structural connections (in steel structures), and connections among different structural elements, non structural element disposal and acceptable constitutive relationships for design. While the first ones of these matters are linked to a geometrical survey, the last one it is connected with the definition of a correct procedure for structural tests. In the present paper the knowledge factor in a case of a strategic building, an important school in a seismic region, Marche Region, is discussed. The case-study building is a more complex one: portions of historical and recent masonry with RC floors are connected with a prevalent infilled RC frame. Results of a wide experimental tests campaign will be discussed and some indications for material qualification will be pointed out.