Impact of Dynamic Multiaxial Excitation on the Performance of a High Damping Rubber Bearing


Abstract eng:
In an earthquake event, base isolators installed under a building are subjected to dynamic multiaxial excitation. The response of an isolated building or bridge can impose deformations in multiple degrees of freedom simultaneously. Despite this, prototype testing required by current design codes is typically performed under unidirectional dynamic excitation. Since an isolator’s performance parameters are derived from unidirectional testing under constant axial load, it is usually unknown how an isolator will respond when subjected to simultaneous dynamic excitation in multiple degrees of freedom. A high damping rubber (HDR) bearing was tested at the Caltrans Seismic Response Modification Device (SRMD) testing facility on the University of California, San Diego campus. The bearing was subjected to an extensive test protocol, which consisted of a variety of loading conditions to assess the bearing’s properties in each degree of freedom, understand the impact of multiaxial excitation, high velocities, temperature, and axial loading. For the first time at a testing facility, a full scale HDR bearing was subjected to different combinations of dynamic excitation in all six degrees of freedom, representing different loading scenarios. This unique information is used to determine how rotation, torsion and axial loading affect the unidirectional and bidirectional response of the HDR bearing. This paper discusses the horizontal hysteretic force-shear strain response of the bearing subjected to a variety of possible loading conditions in addition to a unidirectional and bidirectional motion, including high overturning moments, torsion, uneven bearing installation or settlement, high velocities and bidirectional loading. A comparison of the bearing’s hysteretic response and performance parameters is made between the bearing subjected to unidirectional or bidirectional loading with the addition of pitch, roll and yaw. The bearing’s axial load and loading rate dependency will also be assesed.

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Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 2769.:
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