|
Title |
Proposal of an Inelastic Eccentricity Ratio Equation for Low-Rise RC Piloti Buildings
|
|
Authors |
권유진(U-Jin Kwon) ; 백종하(Jong-Ha Paik) ; 백은림(Eun-Rim Baek) ; 이상호(Sang-Ho Lee) |
|
DOI |
https://doi.org/10.11112/jksmi.2026.30.5.65 |
|
Keywords |
저층 RC 필로티 구조물; 비탄성 편심거리비; 강성중심 이동; 비틀림 비정형; 비선형 정적해석; 설계편심거리 Low-rise RC piloti building; Inelastic eccentricity ratio; Center of rigidity shift; Torsional irregularity; Nonlinear static analysis; Design eccentricity |
|
Abstract |
This study proposes an equation for estimating the inelastic eccentricity ratio of low-rise reinforced concrete (RC) piloti buildings by evaluating the shift of the center of rigidity and the resulting variation in eccentricity during inelastic behavior. A low-rise RC piloti building with an eccentrically placed core wall was considered, and three-dimensional nonlinear static analyses were conducted with plan aspect ratio, wall placement, wall-to-total rigidity ratio, and wall-to-total strength ratio as the main variables. The analysis results showed that the center of rigidity did not remain fixed at its initial elastic position after member yielding. When the wall yielded first, the eccentricity decreased, whereas when the weak-side columns yielded first, the eccentricity increased. In particular, as the wall-to-total strength ratio increased, the likelihood of premature yielding of the weak-side columns increased, resulting in a larger inelastic eccentricity ratio. In addition, a relative comparison between the KDS-based design eccentricity and the inelastic eccentricity considering the shift of the center of rigidity showed that the KDS-based value was larger in most models, whereas the opposite relationship was observed in some models with a high wall-to-total strength ratio. Based on the upper envelope of the nonlinear static analysis results, an equation for the inelastic eccentricity ratio was proposed using the wall-to-total strength ratio as the primary variable, with coefficients classified according to wall placement. The proposed inelastic eccentricity ratio is intended not to directly replace the current design eccentricity, but to serve as a fundamental index for quantitatively evaluating eccentricity variation caused by inelastic stiffness redistribution and the shift of the center of rigidity.
|