نوع مقاله : یادداشت فنی
1 دانشکده فنی و مهندسی عمران- دانشگاه خوارزمی
2 دانشکده فنی و مهندسی - دانشگاه خوارزمی
عنوان مقاله [English]
This paper discusses the effect of physical characteristics of near-field earthquake records on response parameters of braced tube structural systems. The structural systems were selected and designed in 20- and 30-story steel models. The studied structures are located in Tehran based on the soil type II. The models have been designed using the lateral load distribution which is specified in the Iranian seismic code 2800. The section profiles of members and connections of all structural models have been designed according to the Iranian national building code (steel structures - division 10). In this research, the dynamic response parameters of the studied models, have been assessed and presented based on conducting a number of non-linear time history analyses. The selected strong ground motions have been recorded in both near- and far-fault areas, containing a variety of pulse type features in their time history. The main characteristic item in selection of strong ground motions for performing non-linear time history analyses is the existence of high amplitude and long-period pulse or pulses in the ground velocity time history.Braced tube structural systems are, in fact, one of the most efficient structural forms used for multi-story, especially tall buildings. Studying the manners of the seismic behavior of mega brace elements under influence of strong near-field records, is a research subject to improve the design parameters of innovative bracing systems in mid-rise and tall buildings. Combining framed tube systems with mega brace elements causes a better performance in terms of the vulnerability index compared to application of large ordinary arranged bracing systems. The illustrated outputs of the analyzed structural models contain the maximum base shear, the maximum acceleration, and velocity of all stories as well as the maximum inter-story drift. Mega braced framed tube structures, which are designed based on ``limitations on relative seismic displacement of the story levels'' and the ``strong column - weak beam'' rules, have a more convenient performance under powerful earth movements in near-fault zones.