Advanced Steel Construction

Vol. 7, No. 2, pp. 192-205 (2011)


EFFECT OF DAMPERS ON SEISMIC DEMAND OF SHORT PERIOD STRUCTURES IN DEEP COHESIONLESS SITES

 

N.S. Armouti

Associate Professor of Civil Engineering

University of Jordan, Amman 11942, Jordan

(Corresponding author: E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. )

 

Received: 18 October 2010; Revised: 26 December 2010; Accepted: 3 January 2011

DOI:10.18057/IJASC.2011.7.2.6

 

ABSTRACT:

Seismic behavior of short period structures with dampers founded on deep cohesionless soil is investigated. A Single bay frame with diagonal damper that represents short period structures is evaluated in response to the excitation of a set of earthquake records. The frame system is modeled as a Generalized Single Degree of Freedom System, and is subjected to five earthquake records representative of deep cohesionless site conditions. The relationship between the force modification factor and the global ductility demand for short period structures founded on deep cohesionless soil, in the presence of dampers, tends to approach those of long period ones. Compared with seismic demand under general site conditions, short period structures founded on deep cohesionless soil show less seismic demand and lower sensitivity to earthquake excitations. Similar to seismic demand in general site conditions, and except for period of 0.1 second, short period structures in deep cohesionless sites with dampers having damping ratios higher than 20% tend to keep the structural response in the elastic range even for high values of force reductions. Seismic code provisions should be revised to account for short period effect under seismic excitation.

 

Keywords:Ductility demand, seismic demand, short period, dampers, deep cohesionless soil

 

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