جستجو در تالارهای گفتگو

Introducing a New Approach for Modelling the Near Field Effects in Probabilistic Seismic Hazard Analysis Original Article, D90 Mehri Dehno A., Mahdavi Adeli M. Journal. Civil Eng. Urban. 4(6): 592-598. 2014 ABSTRACT: In definitions of seismic hazard analysis, if the site distance from the fault causing earthquake is short, that site will be considered near fault. The recorded results of previous earthquakes have shown that in such site, the structures show very complex and different behaviour from far field area such that it is required to consider near fault seriously and independently. So far, various studies have been carried out to present a method for reliable modelling of near fault behaviour including the present study. In fact, so far, no reliable and definite method has been proposed for modelling of near field effects in probabilistic seismic hazard analysis and this study aims to take some steps in this area. The present study proposes a new solution based on combined use of both spectral attenuation relations, i.e. spectral attenuation relations with near field effect and spectral attenuation relations lacking near field effects, for calculation of probabilistic seismic hazard analysis. The results of this study indicate the capability of this new idea in modelling of near field effects for reliable estimation of seismic hazard. The results of this study show that the use of attenuation relations of near field, individually, for seismic hazard analysis, increases the spectral acceleration tangibly and unacceptably and is not much reliable. Thus, to overcome this deficiency, one can claim that the best solution for consideration of near field effects is to use the combination of both near and far field attenuation relations according to the proposed model in this study. Keywords: Earthquake, Fault, Near Fault, Probabilistic Seismic Hazard Analysis, Attenuation Relations منبع: [Hidden Content] دانلود: [Hidden Content].,%204%20(6)%20592-598,%202014.pdf

Study of Non-linear Dynamic Behavior of Structures with Steel Shear Wall under the Near Fault Earthquakes Original Article, C55 Soltani P. and Tabatabaei Mirhosseini R. Journal. Civil Eng. Urban. 3(6):372-379. 2013 ABSTRACT:This paper deals with study of the steel shear walls and dynamic analysis of such structures under the earthquakes near fault. The studied frames in this paper have a span in 4-meter width and 3-meter height and are included 3 spans. We studied the dynamic of frames after modeling the frames in ABAQUS and giving the earthquake acceleration records near Kobe, Lomaprieta, and Northridge. The results showed that the increase of number of storey increases maximum storey displacement of moment frames. The increase of thickness the shear wall also will decrease the displacement of maximum storey because of decreasing the non-linear effects of shear wall and the delay on submission. Therefore, Base shear in moment frames of 3, 6, and 12-storey, not only depends on maximum acceleration and acceleration records, but also depends on the form of acceleration records. By increasing the number of the storey, this efficacy will be decreased so that the maximum acceleration would be more effective on the storey shear increase or decrease. We can say, by increasing the number of storey of vibration mode, maximum acceleration of storey has the regular process in each 3 acceleration record. It seems that the acceleration of storey not only is based on the type of acceleration record but also is based on the other elements such as increasing the thickness of shear wall and number of the storey. Maximum response in the last storey would not that change by increasing the thickness of shear wall but in the response of other storey, has 6 storey especially storey 3, 4, and 5 in the frame. We can conclude that acceleration of the storey compared to acceleration of column has had the increasing process, by watching the response of acceleration record. The increase of shear wall also decreases the acceleration of storey. Keywords:Dynamic Analysis, Near Fault, Steel Shear Wall, ABAQUS Software, Base Shear منبع: [Hidden Content] دانلود: [Hidden Content].,55-372-379.pdf J. Civil Eng. Urban.,55-372-379.pdf