by Ceylan YeÄŸinsu
OluÅŸturulma Tarihi: Haziran 24, 2009 00:00
ISTANBUL - Foreign experts at a recent earthquake conference praised Turkey for its programs and research methods concerning seismic safety of buildings, but Turkish experts were more critical, saying many buildings continue to be built without sufficient safety measures.
The International Earthquake and Tsunami Conference, organized by a variety of engineering councils, began Monday with the aim to prevent losses from earthquakes through improved civil engineering practices.
The main focus of the three-day conference in Istanbul is on the Millennium Development Goals.Â
Millennium Development Goals include goals such as seismically safe schools, hospitals and dwellings, which will be discussed following a series of presentations from an international panel of engineers.
Expert Keya Mitra from India’s Bengal Engineering Science University highlighted that before measures can be taken to strengthen buildings, it is important to perform seismic assessments on structures that have experienced earthquakes in the past. Research using a rating system and carried out by Mitra in India showed that taller buildings and buildings with basements are more resistant to earthquakes.
When asked about building structures in Istanbul, Mitra told the Hürriyet Daily News & Economic Review that it was obvious there were vulnerable buildings in Istanbul, especially those that are poorly maintained. But, she said, the research presented by Turkish engineers at the conference is promising and ongoing.
The Turkish Chamber of Engineers’ Istanbul branch President Cemal Gokçe said that despite the extensive research, Turkey still has a long way to go in producing sustainable solutions. Gokçe highlighted that many new buildings are not implementing seismic safety measures.
"These buildings are just as vulnerable as older building that are poorly maintained and have undergone corrosion," Gokçe said at the conference on Monday. According to Gokçe, a pressing issue is that material that is more resistant to earthquakes is not being used in construction. "Often safe material that is approved by earthquake safety standards are sacrificed for financial gain."
A director within Iraq’s Environment Ministry, Essa Raheem Dakheel, commented that despite not knowing the ins and outs of building structures in Istanbul, at first glance it became apparent that there are sporadic differences between buildings in Istanbul that will as a result all be affected differently in the case of an earthquake.
Dakheel told the Daily News that such conferences were important for areas such as Istanbul that are close to fault zone to share ideas about earthquake resistance methods. "Japan is an expert in this field," Dakheel said. "Turkey can learn a lot from them."
Academic Mert Özcan told the Daily News that often seismic isolation techniques are implemented in Turkish buildings. This is a system that uses lead rubber bearings to increase a structure’s seismic performance. Two components, natural rubber and lead core, supply low stiffness, which increases the building’s resistance to vibration. Özcan told the Daily News that conferences such as these are important for developing ideas and sharing new ideas with different engineers from other countries.
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While the conference covered a vast number of topics, an important focus for Istanbul was the Marmaray tunnel project. A presentation delivered by doctoral students Zeynep S. Buket from the Yuksel Project International shows different earthquake resistance methods that have been considered for the underwater tunnel that will connect the European and Asian sides of Istanbul.
Istanbul is located 20 kilometers away from the north Anatolian fault zone that runs from east to west of the Princes’ Islands in the Marmara Sea; the Marmaray project sits in a high-risk zone that has the potential to be shaken by a severe earthquake. According to the presentation, the tunnel is modeled with a three-dimensional beam element and the ground has been fitted with a spring element. This structure would allow damage on the tunnel to be easily observed and repairs carried out.
Tsunamis were another focus of the conference. During a discussion panel, experts pointed out that one-third of tsunamis that have taken place in the past 3,000 years have taken place in the Marmara Sea. The keynote speakers in the panel pointed out that it is important to research the characteristics of nearby failed tsunamis, which are crucial to the research in comprehensive tsunami modeling. Another emphasis of the panel was that it is crucial to determine source points under the Marmara Sea in order to determine potential effects and trends of tsunamis.
The conference, held at Istanbul’s Technical University, will conclude today with a focus on buildings’ seismic isolation, seismic risk mitigation and disaster mitigation policies.