Izvorni znanstveni članak
https://doi.org/10.13167/2024.28.2
Fundamental period equations for plan irregular moment-resisting frame buildings
Jahanvi Suthar
orcid.org/0000-0002-7959-0415
; Nirma University, Department of Civil Engineering, Institute of Technology, Ahmedabad-382481, Gujarat, India
Sharadkumar Purohit
orcid.org/0000-0002-2678-4320
; Nirma University, Department of Civil Engineering, Institute of Technology, Ahmedabad-382481, Gujarat, India
Sažetak
The fundamental natural period of oscillation is a critical parameter in evaluating the design base shear of buildings. Worldwide seismic design codes typically employ height-based empirical formulas to estimate this period for various building categories, without distinguishing between regular and irregular buildings. This study proposes a formula specifically for reinforced concrete (RC) moment-resisting frame (MRF) buildings with dominant re-entrant corner type plan irregularity. A total of 190 re-entrant corner dominant building models with different shapes (C-, L-, T-, and PLUS-type), heights, and floor configurations were prepared, and eigenvalue analysis (EVA) was conducted. The fundamental natural period of oscillation for each model was evaluated and compared with the height-based formulas from seismic design codes and the period–height relationship proposed in existing literature. A nonlinear regression model, using a multi-variable power function, is proposed to estimate the fundamental natural period for these re-entrant corner dominant building models. This model considers the A/L ratio in both directions of the building, along with its height. Both unconstrained and constrained regression analyses were performed to derive a formula that best fits the fundamental natural period data. The study recommends that the unconstrained best-fit minus one standard deviation curve can conservatively define the fundamental natural period of oscillation for re-entrant corner dominant RC building models. The equation defining this curve has the potential to replace the existing seismic design code-based period-height formula.
Ključne riječi
fundamental natural period; plan irregularity; re-entrant corner; regression analysis
Hrčak ID:
314653
URI
Datum izdavanja:
28.2.2024.
Posjeta: 109 *