Experimental Study of Secondary Systems in Base-Isolated Structure

This work investigates the response of secondary systems attached to a base-isolated, six-story model structure that is subjected to base motions. The secondary systems are modeled by cantilevered, inverted pendulums. They have natural frequencies and mass ratios that span a wide range of values. The scaled model structure is base-isolated through the use of sliding Teflon disc bearings coupled with restoring helical springs. The structural system is placed on a seismic simulator and is subjected to several prerecorded earthquake accelerograms. Time histories and frequency spectra for the secondary systems and their supporting floors are presented. Subsequently, a numerical model is developed to reproduce the results obtained from the experiments. The level of agreement between numerical and experimental results indicates that the numerical model can be used for the construction of floor response spectra (FRS) for the secondary systems. The experimental results and the numerical studies show that under most circumstances, this novel structural base isolation system reduces the effects of vibrations in the secondary systems.

[1]  Luis E. Suarez,et al.  Eigenproperties of non‐classically damped primary structure and equipment systems by a perturbation approach , 1987 .

[2]  Andrei M. Reinhorn,et al.  Teflon Bearings in Base Isolation II: Modeling , 1990 .

[3]  James M. Kelly,et al.  Equipment response spectra for nuclear power plant systems , 1980 .

[4]  T. T. Soong,et al.  Seismic response of secondary systems , 1988 .

[5]  James M. Kelly,et al.  Sliders and tension controlled reinforced elastomeric bearings combined for earthquake isolation , 1990 .

[6]  M. P. Singh,et al.  Review paperSeismic design of secondary systems , 1988 .

[7]  James M. Kelly,et al.  Aseismic base isolation: review and bibliography , 1986 .

[8]  Andrei M. Reinhorn,et al.  Teflon Bearings in Base Isolation I: Testing , 1990 .

[9]  Armen Der Kiureghian,et al.  Dynamic Response of Multiply Supported Secondary Systems , 1985 .

[10]  James M. Kelly,et al.  Control of seismic response of piping systems and components in power plants by base isolation , 1980 .

[11]  M. P. Singh.  Seismic Design of Secondary Systems , 1988 .

[12]  L. M. Briggs.  Seismic Response Spectra for Equipment Design in Nuclear Power Plants , 1971 .

[13]  M. Khodaverdian,et al.  Dynamics of resilient‐friction base isolator (R‐FBI) , 1987 .

[14]  Andrei M. Reinhorn,et al.  STUDY OF SLIDING BEARING AND HELICAL-STEEL-SPRING ISOLATION SYSTEM , 1991 .

[15]  L. Suárez,et al.  Dynamic Synthesis of Nonclassically Damped Substructures , 1989 .

[16]  Michael C. Constantinou,et al.  Experimental Study of Friction‐Pendulum Isolation System , 1991 .

[17]  Goodarz Ahmadi,et al.  Floor response spectra for base‐isolated multi‐storey structures , 1990 .

[18]  Stephen A. Mahin,et al.  Seismic Response of Light Subsystems on Inelastic Structures , 1985 .

[19]  Armen Der Kiureghian,et al.  Dynamic Analysis of Light Equipment in Structures: Response to Stochastic Input , 1983 .

[20]  James M. Kelly,et al.  Seismic response of light internal equipment in base‐isolated structures , 1985 .

[21]  James M. Kelly,et al.  Response spectra design methods for tuned equipment-structure systems , 1978 .