this paper examines differences in performances of a range of torsionally stiff and flexible single story buildings designed with the provisions of iranian standard 2800. seismic nonlinear dynamic time history behavior of eight building models subjected to seven horizontal bi-directional design spectra compatible ground motions are investigated. these models cover a wide range of very torsional...

The present study evaluates how the soft first story irregularity condition should be defined: (a) as a significant reduction of the lateral shear stiffness of all resisting frames within a given story, as established in the seismic provisions of Mexican building codes or, (b) as a substantial reduction of the lateral shear stiffness of one or more resisting frames within a given story, as prop...

Abstract—The optimal design procedure of buckling restrained braces (BRBs) in reinforced concrete (RC) building structures can provide the distribution of horizontal stiffness of BRBs at each story, which minimizes story drift response of the structure under the constraint of specified total stiffness of BRBs. In this paper, a simple rule is proposed to convert continuous horizontal stiffness o...

The present study assesses the seismic performance of steel moment resisting frames (SMFs) retrofitted with different bracing systems. Two structural configurations were utilized: ordinary concentrically braces (OCBFs), buckling-restrained braces (BRBFs). A 7-story and 18-story steel perimeter SMFs were designed with insufficient lateral stiffness to satisfy code drift limitations in high seism...

A frequency-domain method of physical-parameter system identification is developed for three-dimensional building structures with stiffness eccentricity. Equations of motion in the time domain are transformed into the frequency domain. The dynamic equilibrium of the free body above the j-th story is used to identify the j-th story stiffness and damping. It is required to measure the horizontal ...

In this study, constant-ductility optimization algorithm under a family of earthquake ground motions is utilized to achieve uniform damage distribution over the height of steel moment resisting frames (SMRFs). SMRF structures with stiffness-degrading hysteric behavior are modeled as single-bay generic frame in which the plastic hinge is confined only at the beam ends and the bottom of the first...

the present study assesses the seismic performance of steel moment resisting frames (smfs) retrofitted with different bracing systems. two structural configurations were utilized: ordinary concentrically braces (ocbfs), buckling-restrained braces (brbfs). a 7-story and 18-story steel perimeter smfs were designed with insufficient lateral stiffness to satisfy code drift limitations in high seism...