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Development of Seismic Criteria for Seismic Responses of Regular and Irregular Structures in Plan considering Vertical Component of the Near-field Records Maryam Firoozi Nezamabadi; Fariborz Yaghoobi Vayeghan Field observations of the incurred damages to the buildings and bridges due to earthquakes in near field show there are various failure modes which are in relation to the forces caused by vertical component. While vertical component of earthquake for ordinary buildings in most seismic regulations and standards is not considered. Therefore, in the current study the effects of vertical and horizontal components of earthquake on regular and mass asymmetric structures are investigated simultaneously. The study considers a model of one-story structure with 3 degrees of freedom, lateral displacement, torsional displacement of roof level and vertical displacement, on a rigid foundation. It is concluded that for all such structures in the near-fault zones, the effect of vertical component must be considered. In case of stiff structures, the effect of the force on displacement of such structures is of importance and the effect of vertical component can be disregarded. The use of vertical design response spectrum to calculate the vertical forces caused by near field earthquakes is also recommended. منبع دانلود JSEG341427657400.pdf

The Effect of Vertical Component of Earthquake on Continuous and Monolithic Frame Bridges A Delnavaz; A Rahaee Performance of structures during recent earthquakes shows that the effect of vertical component of earthquake (VCE) could be considered as one of the main causes of bridges collapse. In most of bridge design codes, for seismic analysis of bridges, VCE is not taken into account or a distinguished method isn’t presented for assessment of VCE. In the present work, the effect of VCE on two existing bridges, one with continuous deck and the other with monolithic frame system, was studied. The first model consisted of a pre-stress bridge in which the superstructure was connected rigidly to piers. The super structure consisted of 3 spans with length of 16, 48 and 16 m. The end of side slabs was put on abutments. The second model was a bridge with steel deck and concrete piers. The bridge superstructure was composed of I girder beams and in-place concrete slab. The beams were placed on 3 piers located 24 m far from each other, continually. In both models, the effect of VCE was studied considering the 3 acceleration of Tabas, Northridge and Kobe earthquakes and using linear and nonlinear time history and spectrum analysis on 3D models. In each analysis, the model was analyzed considering the 3 component and 2 horizontal components of earthquakes separately. The ratio of the difference of results in two analyses to the result of bridge response under its weight (DL) was compared. Through this method the amount of VCE effect on affected elements (according to statistical system of bridge) was found out. منبع دانلود JSEG251348691400.pdf