ALPHA CONSTRUCTIONS S.A.

Earthquake engineering has advanced sufficiently in recent years, so as to ensure that well-detailed, newly designed structures usually exhibit adequate strength, stiffness and ductility to withstand severe ground motion. Nevertheless, the vast majority of the existing building stock has been built many years ago, when engineering expertise was not at todays level of knowledge and the safety regulations were less stringent. Consequently, for the structures designed according to older codes the focus had been placed exclusively on the vertical gravity forces, with little or no consideration for the lateral resistance system. Moreover, even if seismic loads have been explicitly considered in the design for relatively modern structures, it is most likely that these structures do no longer meet the constantly updated regulations, since the rapid progress in the field of earthquake engineering during the last two or three decades has radically altered the design philosophy and standards worldwide.

As a result, the vast majority of the building stock exhibits significant deficiencies (reduced resistance to seismic loads, small stiffness or ductility, soft storeys - pilotis) that render them highly vulnerable in seismic events of high intensity, the most characteristic example being the collapse of several buildings during the 1999 earthquake of Athens.

It is important to stress that the field of structural interventions requires specialised know-how and expertise that is beyond the average level of knowledge. Particular attention is needed in the selection of the intervention scheme, since erroneous decisions may not only be proven ineffective, but also increase, rather than decrease the overall vulnerability of the structure.

ALPHA CONSTRUCTION, investing in its high expertise in earthquake engineering, undertakes strengthening interventions, combining specialised knowledge both in design and construction.

An important factor in the consolidation of the position of ALPHA CONSTRUCTION amongst the leader in the field of repair and strengthening is its close collaboration with companies and universities specialised in in the seismic analysis of structures (Seismosoft ltd. Seismic Technology Laboratory at the National Technical University of Athens, European Centre for Research and Training in Earthquake Engineering-EUCENTRE) and the technology of construction chemicals.