NEHRP Clearinghouse
- Title
- Earthquake Response of Torsionally-Coupled Buildings.
- File
- PB90208638.pdf
- Author(s)
- Hejal, R.; Chopra, A. K.
- Source
- National Science Foundation, Washington, DC., December 1987, 354 p.
- Identifying Number(s)
- UCB/EERC-87/20
- Abstract
- The elastic response of torsionally-coupled, one-story framed buildings to earthquake ground motion is presented for a wide range of values of the various system parameters, including the beam-to-column stiffness ration parameter which characterizes the degree of frame action. An effective procedure is developed for estimating the maximum response of a class of torsionally-coupled, multi-story buildings due to earthquake ground motion characterized by smooth response spectra. Centers of rigidity, centers of twist, shear centers and static eccentricities are defined and procedures developed to determine their locations for one-story and multi-story buildings of general plan layouts. It is found that the various centers at each floor of a multi-story building generally do not coincide; their locations not only depend on the geometric and stiffness characteristics of the building but also on the height-wise distribution of lateral forces. Thus, static eccentricities cannot be uniquely determined for multi-story buildings. Since torsional provisions in most building codes are based on the evaluation of static eccentricities, the provisions should strictly be applied to a special class of buildings. Further work is necessary to develop code provisions for buildings not belonging to this special class.
- Keywords
- Response spectra; Framed structures; Eccentricity; Elastic analysis; Earthquake engineering; Shear modulus; Stiffness; Static structural analysis; Lateral pressure