Building contents and nonstructural components are known to be vulnerable during seismic events. Of particular concern is computer and network equipment that is critical in the post-earthquake recovery process. A solution for mitigating the seismic hazard to such systems is rolling-type isolation systems (RISs), but the characterization of RISs with realistic loading conditions and system setups is not well documented. An experimental parametric case study was performed varying the mass eccentricity, the number of cabinets, and the damping to simulate in-service conditions. A series of free response tests was performed using an abrupt shake table displacement (pulse) along with forcedmore »
Evaluation of Rolling-Type Isolation Systems for Seismic Hazard Mitigation
Nonstructural components within mission-critical facilities such as hospitals and telecommunication facilities are vital to a community's resilience when subjected to a seismic event. Building contents like medical and computer equipment are critical for the response and recovery process following an earthquake. A solution to protecting these systems from seismic hazards is base isolation. Base isolation systems are designed to decouple an entire building structure from destructive ground motions. For other buildings not fitted with base isolation, a practical and economical solution to protect vital building contents from earthquake-induced floor motion is to isolate individual equipment using, for example, rolling-type isolation systems (RISs). RISs are a relatively new innovation for protecting equipment. These systems function as a pendulum-like mechanism to convert horizontal motion into vertical motion. An accompanying change in potential energy creates a restoring force related to the slope of the rolling surface. This study seeks to evaluate the seismic hazard mitigation performance of RISs, as well as propose and test a novel double RIS. A physics-based mathematical model was developed for a single RIS via Lagrange's equation adhering to the kinetic constraint of rolling without slipping. The mathematical model for the single RIS was used to predict the response more »
- Award ID(s):
- 1663376
- Publication Date:
- NSF-PAR ID:
- 10272965
- Journal Name:
- The University of Oklahoma Libraries
- ISSN:
- 0270-6989
- Sponsoring Org:
- National Science Foundation
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Loss of operation or devastating damage to buildings and industrial structures, as well as equipment housed in them, has been observed due to earthquake-induced vibrations. A common source of operational downtime is due to the performance reduction of vital equipment, which are sensitive to the total transmitted acceleration. A well-known method of protecting such equipment is seismic isolation of the equipment itself (or a group of equipment), as opposed to the entire structure due to the lower cost of implementation. The first objective of this dissertation is assessing a rolling isolation system (RIS) based on existing design guidelines for telecommunicationsmore »
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