Effect of Plan Geometry on High Rise Buildings Dynamic Response

Abstract

This thesis studies the effect of Plan geometry on high rise buildings behavior and Response through studying the response modification factor and its components (ductility factor Rμ and overstrength factor Rs) through analytical study for number of different plan geometry buildings (square, Equilateral triangle and circular plans) subjected to seismic forces under the same conditions of materials, loads, plan area, number of stories, story height and structural system by resisting gravity loads by shear walls and columns and resisting seismic forces by shear walls only (Building Frame System) with flat slab using reinforcement ratio of 1.0% for shear walls. The ductility, overstrength and response modification factors are calculated through performing nonlinear static pushover analysis to three dimensional finite element models for the buildings with plan geometries under study using ETABS 2016 V16 analysis and design program taking into consideration the inelastic material point nonlinearity represented in plastic hinges for frame elements and fiber hinge for shear wall, the study was conducted as per IBC/ASCE 7-5 and ACI 318-08 for 15 and 30 story models and as per ECP-201/ ECP-203 for the 15 story models. The study concluded that the response modification factor and its components are affected significantly by building plan geometry and shear wall thickness, the value of R is inversely proportional to number of stories (the value of overstrength factor Rs decreases with the increase