A PARAMETRIC STUDY OF EARTHQUAKE IMPACT IN TWO ADJACENT BUILDING WHIT REGARD TO THEIR TORSIONS

Most buildings are often built without following the sufficient separation distance and during earthquake two or more adjacent buildings impose impacts on each other and cause extra internal stresses which are mostly ignored in structural plans and computations. In fact, buildings especially those with different dynamic properties respond differently during earthquake. Given the placement of Iran on the earthquake belt and with regard to the vertical development and extension of cities through constructing high-rise buildings in our country, research on impact seems indispensible. In this article, we have studied the effect of impact on the displacement and torsion of two adjacent buildings. In order to do so, sample couples of (10 & 13 floors), (10 & 15 floors), (7 & 10 floors) and (7 & 15 floors) were modeled next to each other, were connected to each other by Gap axial elements (only compressive) and were then designed by ETABS Ver 9.2, it should be mentioned that the regulation ACI-318 and Standard 2800 were used I designing buildings. Later, the analysis of the nonlinear modal time history under the seismogram of Bam, Tabas and Vally earthquakes with 5% damping was carried out. Research findings show that impact causes displacement and torsion reduction in all stories in the taller building along the impact between two buildings while torsion decreases in the shorter building and commenting on the obtained responses for displacement will depend on such factors as the seismograms type and the heights of two adjacent buildings. Perpendicular on the impact between buildings, the impact causes displacement increase in all stories in the taller building and for all seismograms. However commenting on displacement increase or decrease in the shorter building depends on the seismograms type and the number of stories (height) of the two adjacent buildings.

Keywords:

Impact , Dynamic analysis time history , Displacement , Torsion , Gap element