Formulation of damping reduction factor for the Algerian seismic code

Autor: B. Benahmed
Rok vydání: 2018
Předmět:
Zdroj: Asian Journal of Civil Engineering. 19:375-385
ISSN: 2522-011X
1563-0854
DOI: 10.1007/s42107-018-0023-6
Popis: The high-damping elastic response spectra have several important applications in evaluating the design of earthquake resistant structures. They are derived from the reference spectrum for damping equal to 5% using the damping reduction factor (DRF). Most damping reduction factors currently used were derived from observing the effects of viscous damping on the maximum response elastic of SDOF systems subjected to earthquakes. This factor depends on the equivalent viscous damping of the structure, its vibration period, the epicentral distance, earthquake magnitude, and other parameters), and several different expressions of damping reduction factors were proposed and then adopted in a form somewhat different in seismic codes. The aim of this work is to propose a DRF formulation for the Algerian Seismic Regulations (RPA). First, four sets of natural records are selected from the world ground motion database PEER considering the soil classification of RPA. The selection is based on the shear wave velocity Vs30, which is the parameter used for the soil classification in RPA. These records are compatibles (on average) with RPA response spectra for soil classes. Afterward, those records have been used to estimate the response spectrums with different values of damping ratio (7.5, 10, 15, and 20%). Then, the DRF values are calculated for all records for the range of period of interest in structure seismic design. Those values of DRF are used on nonlinear regression to find a formula of the DRF values in a function of the structure dynamic characteristics (damping ratio and vibration period). A comparison between the proposed formulation and some formulations from the literature is presented, and the results were discussed in terms of the errors between the results from each formulation and the exact results.
Databáze: OpenAIRE
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