Seismic Analysis of Non-Proportionate Eccentric Buildings

Abstract

A simple procedure is presented for estimating frequencies and the peak values of base resultant forces of eccentric non-proportionate buildings due to earthquake ground motions. Multi-story buildings composed by a number of bents with different stiffness matrices do not belong to the special class of proportionate buildings, which can be analyzed by a simple methodology developed in the past. This paper extends this methodology to all types of medium height buildings and is shown that their maximum response can be derived from the analysis of two single-story modal systems. The accuracy of the proposed method is illustrated in mixed-bent-type example structures and comparisons are made with the accurate results obtained by response spectrum analyses using the SAP2000 computer program.