Integrated Design Methodology for Isolated Floor Systems in Single-Degree-of-Freedom Structural Fuse Systems

Keywords: Structural fuse systems.  Single degree of freedom (SDOF) systems.  Passive hysteretic energy dissipation (PED) devices.  Seismic performance.  Displacement demands.  Flooring systems.  Acceleration.  Nonstructural components.  Seismic isolation systems.

Abstract: To protect the acceleration sensitive equipment, a possible solution may be to combine the stiffening of structures using passive hysteretic energy dissipation (PED) devices with a strategy of introducing isolated floors in the rooms where such acceleration-sensitive equipment is located. Two kinds of isolated floor systems were studied in this research. Characterization tests were first conducted on two kinds of isolated floor systems to define their mechanical behavior properties, from single isolators to complete systems. The experimentally obtained mechanical behavior was then simulated in computer programs. Models of single-degree-of-freedom (SDOF) structural fuse frames with implementation of these two isolated floor systems were developed. A number of parametric studies were then conducted on these combined systems to determine the preferred design parameter values to be used in the design of such structural fuse frames coupled with isolated floors, and to establish how the combined systems behave under different mass ratios of the isolated floor system to the base SDOF structural fuse structure. Finally, combined design concepts considering both the design of the base SDOF structural fuse structure and the design of the isolated floor system on top were developed for each kind of isolated floor system.