Partial Floor Mass Isolation to Control Seismic Stress in Framed Buildings

Partial Floor Mass Isolation to Control Seismic Stress in Framed Buildings

M.C. Porcu

Department of mechanical, Chemical and materials Engineering, University of Cagliari, Italy.

Page: 
157-165
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DOI: 
https://doi.org/10.2495/SAFE-V9-N2-157-165
Received: 
N/A
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Revised: 
N/A
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Accepted: 
N/A
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Available online: 
N/A
| Citation

OPEN ACCESS

Abstract: 

Isolating portions of the floor mass through rigid–plastic connectors may reduce the effects of strong earthquakes on framed buildings. This strategy was shown to be effective for single-storey frames, provided that a reasonably low plastic limit given to connectors and large enough portions of mass be disconnected. The stress reduction is however found to depend significantly on some interrelated parameters and on the given earthquake. By means of an analytical study and a nonlinear numerical investigation involving single-storey frames and four recorded earthquakes, the present paper gives a swift way to estimate the extent of stress reduction that can be achieved under a given earthquake, for preset values of the key parameters. Some empirical formulae are also provided to estimate the peak relative displacement that is reached by the disconnected mass.

Keywords: 

Floor mass isolation, inertia limiters, rigid–plastic connectors, seismic stress control.

  References

[1] Warn, G.P. & Ryan, K.L., A review of seismic isolation for buildings: historical Development and research needs. Buildings, 2(3), pp. 300–25, 2012.

[2] Paglietti, A. & Porcu, M.C., Controlling dynamic stress through plastic limiters. Proc. of the 1st European Conference on Structural Control, eds. A. Baratta. and J. Rodelar, Barcelona, Spain, World Scientific Publishing, Singapore, pp. 483–90, 1996.

[3] Ziyaeifar, M. & Noguchi, H., Partial mass isolation in tall buildings. Earthquake Engineering & Structural Dynamics, 27, pp. 49–65, 1998.

[4] Villaverde, R., Aguirre M. & Hamilton, C., Aseismic roof isolation system built with steel oval elements: exploratory study. Earthquake Spectra, 21(1), pp. 225–41, 2005.

[5] Tian, Z.C., Qian, J.R. & Zhang, L.M., Slide roof system for dynamic response reduction. Earthquake Engineering & Structural Dynamics, 37(4), pp. 647–58, 2008.

[6] Anajafi, H. & Medina, R.A., Comparison of the seismic performance of a partial mass isolation technique with conventional TMD and base-isolation systems under broad- band and narrow-band excitations. Engineering Structures, 158, pp. 110–123, 2018.

[7] Reggio, A. & De Angelis, M., Optimal energy-based seismic design of non-conventional Tuned Mass Damper (TMD) implemented via inter‐story isolation. Earthquake Engineering & Structural Dynamics, 44(10), pp. 1623–42, 2015.

[8] Hashimoto, T., Fujita, K., Tsuji, M. & Takewaki, I., Innovative base-isolated building with large mass-ratio TMD at basement. Int. J. Future Cities Environ. 1, p. 9, 2015.

[9] De Domenico, D. & Ricciardi, G., An enhanced base isolation system equipped with optimal tuned mass damper inerter (TMDI). Earthquake Engineering & Structural Dynamics, 47, pp. 1169–1192, 2018.

[10] Porcu, M.C., Plastic disconnection of story masses for seismic stress control. In Earthquake Resistant Engineering Structures X, 152, WIT Press, 2015.

[11] Porcu, M.C., Numerical assessment of a stress control method based on rigid–plastic inertia-limiters. Proceedings of the 14th Int. Conference on Civil, Structural and Environmental Eng. Computing, Civil-Comp Press, Stirlingshire, UK, Paper 42, 2013.

[12] Porcu, M.C., Reducing seismic stress on buildings through inertia limiters at floor level, earthquake resist. Engineering Structures, IX, 132–333, 2013.

[13] Xiang, P. & Nishitani, A., Seismic vibration control of building structures with multiple tuned mass damper floors integrated. Earthquake Engineering & Structural Dynamics, 43(6), pp. 909–925, 2014.

[14] Chopra, A.K., Dynamics of Structures, Prentice-Hall, New Jersey, USA, 2001.

[15] Paglietti, A. & Porcu, M.C., Rigid–plastic approximation to predict plastic motion under strong earthquakes. Earthquake Engineering & Structural Dynamics, 30, pp. 115–126, 2001.

[16] Porcu, M.C. & Carta, G., A better rigid–plastic estimate for earthquake-induced Plastic displacements. International Journal of Safety and Security Engineering, 2(2), pp. 184–196, 2012.

[17] Porcu, M.C. & Carta, G., Evaluating a rigid-plastic method to estimate the earthquake ductility demand on structures. In Earthquake Resistant Engineering Structures VIII, 120, Wit Press, pp. 261–271, 2011.