Researchers: Thomas Herring, Chen Gu, M. Nafi Toksöz, and Oral Büyüköztürk, Massachusetts Institute of Technology; Jafarali Parol, Abdullah Al‐Enezi, Farah Al‐Jeri, Jamal Al‐Qazweeni, and Hasan Kamal, Kuwait Institute for Scientific Research.
Written by Linda Rowan
25 February 2020
An 86-floor tall, steel-sculpted concrete building in Kuwait was shaken by a moment magnitude 7.3 earthquake far away at the Iran-Iraq border. The building’s shaking was captured by GPS sites, on the top of the building, and others near ground level. The ground shook with amplitudes of about 40 millimeters while the building shook up to 160 millimeters. Shaking was recorded for about 15 minutes after the event. There were two amplitude peaks in shaking motions related to the fundamental modes of the building. Such observations can help to understand a building’s response to an earthquake and to improve building design in response to large stresses.
There are a growing number of skyscrapers in the world. On the Arabian Peninsula, tall buildings are affected by seismic waves from large regional earthquakes. The Arabian plate that includes the peninsula is adjacent to five different major plates and experiences significant seismicity along these plate boundaries.
Ground motions from earthquakes are amplified at the higher levels of skyscrapers. The Al-Hamra Tower in Kuwait City is an iconic, sculpted building reaching a height of 413 meters. The 86-floor concrete structure is reinforced with steel and the foundation is supported by 289 concrete piles driven to depths of 22 to 27 meters below the surface. It is considered the tallest building with such a unique concrete and steel construction.
There is a GPS site at the top of the building (site ALHR) and another GPS on an adjacent building, a mall, which is 43 meters tall (site MLRF). Observations from a nearby GPS site on a two-story building, the Kuwait Institute for Scientific Research (site KISP) and a far away GPS site on a short building in Haifa, Israel (site BSHM) were used to compare responses to the earthquake.
On 12 November 2017 a moment magnitude 7.3 earthquake occurred about 642 km to the north of the Al-Hamra Tower, on the Iran–Iraq border. The GPS site near the building recorded ground shaking with a maximum amplitude of 40 millimeters and the GPS site at the top of the building recorded shaking at the top of the tower with a maximum amplitude of 160 millimeters in the north and east horizontal directions and 30 millimeters in the vertical direction. Building occupants would have experienced two separate and large horizontal shakings over about 5 minutes. The amplitude and timing of the shaking is related to the two fundamental modes of the building. An initial analysis shows no permanent static offset of the building. Additional analysis is ongoing to assess any static offset that may be affected by temperature changes during the shaking. The GPS sites are useful for understanding building response to large earthquakes and other stresses.
Thomas Herring, Chen Gu, M. Nafi Toksöz, Jafarali Parol, Abdullah Al‐Enezi, Farah Al‐Jeri, Jamal Al‐Qazweeni, Hasan Kamal, Oral Büyüköztürk; GPS Measured Response of a Tall Building due to a Distant MwMw 7.3 Earthquake. Seismological Research Letters ; 90 (1): 149–159, doi: 10.1785/0220180147 .
shaking, fundamental mode, GPS
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Last modified: 2020-02-25 16:22:20 America/Denver