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Structural and equipment performance of base-isolated medical facility subjected to strong vertical ground motions

Furukawa, Sachi; Sato, Eiji; Shi, Yundong; Nakashima, Masayoshi

Lisboa, Portugal. WCEE, 2012, paper presented at 15th World Conference on Earthquake Engineering, Lisbon, Portugal, September, 2012., author retains copyright, 2012-09, PDF

A series of full-scale shaking table tests were conducted at the E-Defense shaking table facility on a base-isolated four-story reinforced concrete hospital structure to examine the structural performance and equipment behavior under the vertical motions. The results showed that the vertical floor accelerations of the base-isolated system were dominated by a few mode responses, while several modes contribute to those of the fixed-base system. The lowest vertical natural frequency of the base-isolated system was estimated as 10.7 Hz, with the damping ratio recorded to be 3%. Damages to building contents in the base-isolated system under vertical motions may not be so detrimental in medical service. However some concerns were surfaced out, such as the toppling of containers stored in shelves and jumping of patients lying on the beds, when the maximum vertical floor acceleration exceeded 1 g.

Available online: http://nisee.berkeley.edu/documents/elib/www/documents/201304/furukawa-vertical-hosp.pdf (561 KB)