After the seismic events on February 6, 2023 in Türkiye, our EERI reconnaissance team mobilized on March 13, 2023 to assess the performance of hospitals. The purpose of the trip was to observe structural response, damage, and the effect of earthquakes on hospital functionality. Of primary interest was understanding what characteristics enabled hospitals to continue functioning after the earthquakes, and conversely, what caused hospitals to be evacuated.
Team
The hospital field reconnaissance team included the following structural engineers from the US: Ali Sumer from the Department of Health Care Access and Information of California (HCAI), Maryann Phipps from Estructure, Bret Lizundia from Rutherford + Chekene, Gordon Wray from Degenkolb Engineers, Dr. Ali Roufegarinejad from Forell/Elsesser Engineers, Ricardo Henoch from Skidmore, Owings & Merrill, and Dr. Onder Akinci from SGH. Additionally, we were grateful for the involvement of Professor Volkan Kara from the Cerrahpaşa Medical School of Istanbul University and Yüksel Tonguç from the Turkish engineering firm Promer.
Scope of Reconnaissance Effort
The team’s base of operation was in Adana. From there, the team drove more than 2,000 km to several impacted areas. The cities and towns visited are summarized as follows:
Day 1: Türkoğlu, Kahramanmaraş
Day 2: İskenderun
Day 3: Adana, Dörtyol, Osmaniye
Day 4: Nurdağı, Pazarcık, Gaziantep
Day 5: Adana, Antakya, Kırıkhan
The team observed a total of 23 hospitals with varying levels of structural and nonstructural damage. The sampling of buildings included old and new, large and small, and government, private, and university hospitals. It also included both fixed-base and seismically-isolated hospital buildings. The diverse sampling was intended to be representative of the hospitals in the affected area, but observations depended on level of access and extent of damage.
Structural Systems
The lateral force-resisting systems for the hospitals observed are mainly reinforced concrete moment frames with some shear walls at the stair cores and/or elevator shafts. They have heavy, stiff infill (hollow clay tile), lightweight cellular hollow concrete block, and autoclaved aerated concrete (AAC) at exterior walls and at interior partitions that participated in resisting lateral load. Stairs are also typically concrete without observed slip joints. Foundations include mats, spread footings and grade beams, and piles. In the isolated buildings, the plane of isolation was located either in a crawl space below the lowest occupied floor or at the top of columns in a parking garage below the hospital levels.
Observations on Performance
In general, observed structural damage in the lateral force-resisting system was minimal except for older buildings; however, nonstructural damage was widespread. Closures of hospitals that were still standing were primarily due to damage to unreinforced the heavy, stiff partitions, ceilings, medical equipment, and emergency generators, and disruptions to water, electricity, and gas lines. Three seismically-isolated buildings were observed; all were operational; however, the isolation system displacements were far lower than the system capacities.
From the hospitals that the team visited, 26% (6 of 23) had collapsed, had severe damage, or had been demolished due to the extensive damage.
A large percentage of hospitals had moderate amounts of nonstructural damage with no or minor structural damage observed. The extent of nonstructural damage impeded hospital function. The common use of heavy, stiff partition walls without proper detailing led to a significant amount of damage. Additionally, these walls were used in some cases to anchor equipment and furniture, failure and disconnection of those anchors was observed.
Several hospitals with nonstructural damage were functioning at limited capacity while repairing damage to partition walls. Removing the appearance of cracks restores confidence to patients and staff, but it does not improve resilience against future earthquakes.
Seismically-isolated hospitals had no significant damage and were fully functional after the events The displacements observed were small relative to the capacity of the bearings. It has not yet determined whether these are consistent with the expected displacements given the specified bearing properties and site spectra. There were examples of MEP systems and partitions that were not detailed to accommodate design displacements across the plane of isolation. There were gaps at the moat covers that were infilled with gravel or soil or crossed by sidewalks that would increase resistance to movement. Some of these displacement-incompatible nonstructural installed systems at the isolation plane may be damaged if larger displacements are experienced at the site, hindering full functionality.
Several older hospitals that experienced strong ground shaking collapsed or partially collapsed. In newer hospitals, the structural systems generally provided life-safety (or better) performance, but damage to nonstructural components rendered some buildings unusable. Inoperable emergency generators, extensive damage to interior partitions and exterior cladding, and dislodged ceilings contributed to some hospital evacuations. In addition, nonstructural damage such as cracks in masonry partition walls, had a psychological impact on hospital staff and patients, which in some cases influenced the decision to evacuate.
