Page 121 - Çevre Şehir İklim İngilizce - Sayı 4

Cenk Alhan - Mert Hacıemiroğlu

Figure 4. İstanbul University Hasdal Campus, hospital buildings with seismic isolation and
friction pendulum insulators (Photo: Eksioglu Karel JV Partnership)
Seismic isolation is also widely and successfully applied in bridge-type
structures. Dolce (2001) summarized the seismic isolation applications in some
important bridges and viaducts in Europe. One of the most important of these
bridges is the cable-stayed bridge located on the Tagus River in Portugal with
a main span of 246 m. Design displacement of the isolation system is 250 mm
where High Damping Rubber Bearings were used with a diameter of 950 mm,
the equivalent damping ratio is 10% and the elasticity module is 0.4 MPa which
is a quite low value. The Agrifoglio Viaduct of the Naples-Canosa Motorway
in Italy was also reinforced with an isolation system using elastoplastic sliding
bearings. The Mw=8.8 Chile Earthquake of February 27, 2010 lasted for 140
seconds and the greatest ground acceleration was measured at 0.78g at
Melipilla Station. Although 25 bridges collapsed and many overpasses were
damaged, 12 seismic-isolation bridges located in the earthquake-affected
region exhibited a very good earthquake performance. Only the Cardinal
Silva Henriquez Bridge was slightly damaged, this damage could be easily
repaired when the bridge was under the traffic (Sarrazin et al., 2013).
Approximately 104 seismic isolation structures were built in Türkiye until
2018, including hospitals, airport terminals, bridges and viaducts, and
detailed information about this period was given by Erdik (2017). Erdik et al.
(2018), in another study, revealed the details of two important seismic isolation
projects carried out in Türkiye: (1) Başıbüyük Training and Research Hospital,
İstanbul, the largest hospital building reinforced with seismic isolation in the
world, where a total of 688 lead-core and 154 sliding isolators were used.
(2) Adana City Hospital, with a total of 1552 three-surface friction pendulum
insulators. The developments between 2019-2022 regarding seismic insulated
structures in Türkiye were reported by Sadan (2023), it was informed that an
average of 415 isolators were used per building, he 1915 Çanakkale Bridge
approach Viaducts were constructed with seismic isolation, there is a 16-block

110 The Journal of Environment, Urban and Climate