Analysis and modelling of the seismic behaviour of high ... - Ingegneria
Analysis and modelling of the seismic behaviour of high ... - Ingegneria
Analysis and modelling of the seismic behaviour of high ... - Ingegneria
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5. SEISMIC BEHAVIOUR OF RC COLUMNS EMBEDDING STEEL PROFILES<br />
et al., 1999; Aschheim, 2000; Scawthorn, 2000). Estimates for economic losses<br />
were around 20 billion US dollars. The <strong>of</strong>ficial death toll was over 17,200, with<br />
some 44,000 people injured <strong>and</strong> thous<strong>and</strong>s left homeless. Some 77,300 homes<br />
<strong>and</strong> businesses were destroyed, <strong>and</strong> 244,500 were damaged. The majority <strong>of</strong><br />
deaths <strong>and</strong> injuries were in <strong>the</strong> cities <strong>of</strong> Kocaeli, Sakarya, <strong>and</strong> Yalova, as<br />
reinforced concrete moment-resisting frame buildings behaved poorly during <strong>the</strong><br />
earthquake.<br />
According to <strong>of</strong>ficial estimates, more than 20,000 moment frame buildings<br />
collapsed, <strong>and</strong> many more suffered moderate to severe damage. Three- to seven-<br />
storey apartment buildings were hard hit, although many were constructed in <strong>the</strong><br />
past 20 years. These buildings were probably designed <strong>and</strong> detailed to comply with<br />
<strong>the</strong> requirements <strong>of</strong> <strong>the</strong> building code (TS-500 code, 1975) <strong>and</strong> <strong>of</strong> <strong>the</strong> earthquake<br />
Turkish code (1975) for construction in a first-degree <strong>seismic</strong> zone. Never<strong>the</strong>less,<br />
<strong>the</strong> ductile reinforcement details described in <strong>the</strong> 1975 earthquake code were<br />
rarely observed in buildings inspected after <strong>the</strong> August 17 th 1999 earthquake.<br />
Moreover, many <strong>of</strong> <strong>the</strong> failures <strong>and</strong> collapses <strong>of</strong> engineered construction observed<br />
by <strong>the</strong> reconnaissance team, <strong>and</strong> reported in Sezen et al. (1999), can be attributed<br />
to <strong>the</strong> formation <strong>of</strong> s<strong>of</strong>t first storeys as a result <strong>of</strong> differences in frame systems <strong>and</strong><br />
in-fill wall geometry especially between <strong>the</strong> first <strong>and</strong> upper stories; to <strong>the</strong> realisation<br />
<strong>of</strong> non-ductile details; <strong>and</strong> to <strong>the</strong> utilisation <strong>of</strong> material <strong>of</strong> too poor quality in some<br />
cases. It was clear that <strong>the</strong> Turkish earthquake code provisions were rarely<br />
enforced for <strong>the</strong> engineering <strong>of</strong> commercial <strong>and</strong> residential construction. On <strong>the</strong><br />
basis <strong>of</strong> <strong>the</strong> aforementioned consideration, this last research activity, conducted in<br />
<strong>the</strong> third year <strong>of</strong> <strong>the</strong> Ph.D. course, is part <strong>of</strong> ano<strong>the</strong>r European Project (INERD<br />
Project), promoted by <strong>the</strong> E.U. through <strong>the</strong> E.C.S.C. European Coal <strong>and</strong> Steel<br />
Community <strong>and</strong> R.F.C.S. Research Fund for Coal <strong>and</strong> Steel, that deals with <strong>the</strong><br />
improvement <strong>of</strong> <strong>the</strong> resistance <strong>and</strong> ductility <strong>of</strong> reinforced concrete (RC) structures<br />
using <strong>the</strong> performance <strong>of</strong> structural steel pr<strong>of</strong>iles.<br />
5.2 The INERD project<br />
The European INERD (acronym <strong>of</strong> Innovations for Earthquakes Resistant Design)<br />
project consists in promoting one specific construction measure for lower storeys <strong>of</strong><br />
RC structures, by which steel pr<strong>of</strong>iles would be encased in <strong>the</strong> RC columns in<br />
order to provide <strong>the</strong>m with a basic reliable shear <strong>and</strong> compression resistance. The<br />
general objective is to establish an innovative concept through new st<strong>and</strong>ard<br />
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