“FORCE-DISPLACEMENT TRADE OFF” OF RCC BUILDING LOCATED AT VARIOUS SEISMIC ZONES AND SITE CONDITION ADOPTING TIME-HISTORY ANALYSIS

Abstract

Earthquake-resistant or aseismic design are considered to protect buildings to some or greater extent from earthquakes. The force-displacement trade off of structures located in various seismic zones are different in nature depending on intensity of earthquake. No structure can be fully immune to damage from earthquake, the vulnerability can be reduced for safety and durability. The force-displacement behavior of a particular structure can be modified to withstand seismic occurrence preventing collapse and loss of life. Base isolation or structural vibration control techniques are used to minimize forces and deformations. Instead of conventional design approach, base isolation system is used as passive vibration control system which influences the force-displacement property of structures specially in high seismic zones. The present paper investigates the force-displacement nature of various RCC buildings G+7 & G+15 with base isolation system adopted at support positions. The isolation system has been analyzed using different methods, from equivalent static, response spectrum to non-linear time history method using earthquake acceleration function considering different stiffness and damping properties for G+15 building. The Isolation and deformation ratios considering different isolator stiffness of fixed and isolated support for G+15 building have been plotted for different seismic zones and soil conditions. Particular zone can be selected from the graphs for consideration of optimum design of isolation system for a particular building structure at particular seismic zone and soil conditions. The selection of this optimum region for design of isolation system can play major role in economic and safe anti-earthquake design of structures.