PERFORMANCE BASED DESIGN OF FLAT SLAB-SHEAR WALL SYSTEM

Abstract

Flat slab are being widely used primarily as gravity load resisting system. It is being employed in low seismic prone areas. But its behavior under lateral loading is not satisfactory. So it can be combined with lateral force resisting systems such as shear wall or shear core. In the present study the behavior of flat slab system designed for gravity loading only combined with shear wall is studied using nonlinear static pushover analysis procedure. Three dimensional modeling of flat slab is done by using effective beam width method and transverse torsional member method. For pushover analysis procedure SAP 2000 is used and provisions of FEMA 356, ATC — 40 and ACI 318-05 are used to define user defined hinge properties. After analysis it can be concluded that flat slab building behave as weak beam strong column. Flat slab building without any additional lateral force resisting system could not sustain in maximum considered earthquake for Zone IV. Addition of shear wall increases the strength of combined system and slab can perform well for higher level of earthquake. Maximum drift reduces and the time period decreases as the percentage of shear wall is increases. Increase in thickness of slab also reduces the possibility of punching failure but in this case slab may fail in flexure.