Comparison of fundamental periods of reinforced shear wall dominant building models with empirical expressions

Abstract

Original scientific paper Empirical formulas for the estimation of the fundamental periods have been included in seismic codes, which mainly depend on building height, material (steel, reinforced concrete (RC)) and structural system type (frame, shear wall, etc.). These formulas have been usually derived from empirical data through regression analysis of the measured fundamental period of existing buildings subjected to seismic actions. A parametric study on 480 different RC building models with shear walls was performed with varied parameters: building height, number of bays and the ratio of shear walls area to floor area. The aim of this paper is to verify these empirical expressions, which are given by different authors and seismic codes and to conclude whether the expressions are good enough as a starting assumption for the design of earthquake resistant buildings.Keywords: EN1998-1; fundamental period; parametric study; RC shear walls; structure models Usporedba osnovnih perioda modela zgrada s armiranobetonskim zidovima s empirijskim izrazimaIzvorni znanstveni članka Empirijski izrazi za procjenu osnovnih perioda su sastavni dio propisa za proračun seizmičkih djelovanja te uglavnom ovise o visini, materijalu (čelik, armirani beton) i nosivom sustavu(okvir, posmični zidovi, itd.) građevine. Ovi izrazi su obično nastali iz empirijskih podataka kroz analizu mjerenih osnovnih perioda postojećih građevina pod djelovanjem potresa. Provedena je parametarska studija na 480 modela armiranobetonskih zgrada s posmičnim zidovima s različitim ulaznim podacima: visina zgrade, broj raspona i omjer površine posmičnih zidova i tlocrtne površine zgrade. Cilj ovog istraživanja je provjeriti empirijske izraze različitih autora i seizmičkih propisa u svrhu provjere točnosti izraza kao početnih pretpostavki kod projektiranja potresno otpornih građevina.

Soil foundation and structure interaction effects on the estimating of fundamental period of instrumented buildings

“…The evaluation was carried out with the formulas in ASCE 7-05 for steel and RC MRF, SW buildings, braced frames and other structural types. The differences between the periods from code formula and measured periods of low-to-medium rise buildings were relatively high [27].…”

“…Lee and al. concluded that none of the code formulas examined in their study are sufficient for estimating the fundamental period of apartment buildings with shear wall system SW dominant systems [24]. Crowley and Pinho (2006) have proposed an empirical relationship between period T and height H "T = 0.1H" with a view to assess their validity for use in displacement-based structural assessment.…”

Natural-Hazards Risk Assessment for Disaster Mitigation

“…Similarly, of two structures of the same stiffness, the heavier (greater mass) has a lower natural frequency and a longer natural period. This value can be obtained both with approximate formulas and as a result of numerical analysis [143][144][145][146]. The empirical relations and explanations stipulated in the corresponding design code for each country are given in Table 16.…”

Hysteretic Performance of Hybrid GFRP-Steel Reinforced Concrete Shear Walls: An Experimental Investigation

“…Furthermore, reliable evaluation of the magnitude and effects of the fundamental vibration period for lateral resisting RC structures constitutes an essential step in estimating earthquake-induced forces and assessing their seismic response. The fundamental period of RC structures mainly depends on their mass and effective stiffness; consequently, it depends on their dimensions, morphology, and irregularities, among other factors that may affect their effective stiffness [17]. The period value of RC structures appears in formulas specified in most design codes to compute the design base-shear and resultant lateral forces.…”