Full‐scale shaking table test for examination of safety and functionality of base‐isolated medical facilities

Abstract

A series of full-scale shaking table tests are conducted using the E-Defense shaking table facility on a base-isolated four-story RC hospital structure. A variety of furniture items, medical appliances, and service utilities are placed on the hospital specimen in as realistic a manner as possible. Four ground motions are adopted, including recorded near-fault ground motions and synthesized long-period, long-duration ground motions. The test results show that the base-isolated system performed very effectively against near-fault ground motions due to significant reduction in the floor acceleration response, and operability and functionality of the hospital service is improved significantly as compared with the case observed for the corresponding base-fixed system. Against the long-period ground motion, however, the hospital service is difficult to maintain, primarily because of the significant motion of furniture items and medical appliances supported by casters. Resonance accentuated large displacements and velocities on the floors of the base-isolated system, which causes such furniture items and medical appliances to slide, sometimes more than 3 m, resulting in occasional collision with other furnitures or against the surrounding partition walls. It is notable that a key to maintaining the function of the medical facilities is to securely lock the casters of furniture and medical appliances. E. SATO ET AL. more emphasis on 'experiences' than do other engineering disciplines. As urbanization progresses rapidly, the society becomes denser and as many components that form the society interact with increasing complexity, the resilience of society is naturally lessened. In such an era, the attitude of 'learning from actual earthquake damages' is most likely not acceptable any longer. One alternative is to adjust our attitude to one of 'learning from quasi-actual earthquake damages.' One tool for experiencing such damages is the large shaking table, dubbed E-Defense, developed in Japan after the 1995 Hyogoken-Nanbu (Kobe) earthquake [1,2]. Since its inauguration in 2005, E-Defense has conducted nearly 40 full-scale or large-scale shaking table tests, applied to RC building frames, RC bridge peers, steel building frames, wooden houses and apartments, soil liquefaction, energy facilities, among others, for example [3][4][5][6][7][8]. The tests supply detailed data on the actual behavior and collapse of the tested structures, offering the earthquake engineering community opportunities to assess the actual seismic performance of the structures.Life safety has been of utmost importance in earthquake engineering, but maintaining the quality of life has also become a critical issue in the recent years. Nonstructural damage, business continuity, quick damage assessment, and other issues have been seriously explored, particularly in the context of performance-based seismic design. To achieve enhanced functionality and operability, base isolation has become very popular in Japan. The first base-isolated building structure was ...

A Review of Seismic Isolation for Buildings: Historical Development and Research Needs

“…Thus, the effectiveness of seismic isolation to protect a variety of building content was evaluated directly, rather than by speculation of the influence of recorded responses, such as floor accelerations. In fact, the primary objective of the hospital test program [90] was to examine the performance of hospital equipment, and evaluation of the seismic performance of interacting partition walls, suspended ceilings, and sprinkler piping was a key component of the NEES/E-Defense tests [91]. Second, full scale models are required to realistically reproduce the effects of vertical vibration of the floor system and thus assess the influence of vertical excitation on building content.…”

“…Recently, two independent test programs on full scale isolated buildings with weights of 5,000-10,000 kN have been conducted at National Institute for Earth Science and Disaster Prevention (NIED) E-Defense shaking table of Japan. The first of these test programs evaluated the response of a 4-story R/C hospital building isolated with 4 high damping rubber bearings and 4 natural rubber bearings paired with steel dampers [90]. The second of these test programs, a NEES/E-Defense collaboration, evaluated the response of a 5-story steel moment frame building isolated with (1) 9 triple pendulum bearings (TPBs); and (2) 4 lead-rubber bearings (LRBs) paired with 5 cross linear bearings (CLBs).…”

Seismic analysis, design, and installation of nonstructural components and systems � background and recommendations for future work

“…The test results indicated that the baseisolated system effectively mitigated the damage to hospital components against near-fault ground motions, but dangerous movement of unanchored sliding or rolling equipment was observed during long-period ground, long duration motions. Further information from this test program is available in Sato et al (2011).…”

“…The building superstructure was the same as that tested by Sato et al (2011). However, this test building was outfitted as a medical facility with a wide variety of hospital contents to investigate the effects of vertical response on building contents and nonstructural components.…”

Effect of Ground Motion Directionality on Seismic Response of Base-Isolated Buildings Considering Pounding to Adjacent Structures

“…A number of recent research works that extend the simulation in the more realistic 3D space [10][11][12][13][14][15][16][17][18][19] have been reported. Matsagar and Jangid [10] investigated the seismic response of a single-story asymmetric structure supported on various base-isolation systems during impact with adjacent structures.…”