PERFORMANCE EVALUATION OF A MULTI STOREY CAR PARKING STRUCTURE UNDER STRENGTH IRREGULARITIES BY PUSH OVER ANALYSIS

Abstract

Buildings, which appeared to be strong enough, may crumble like houses of cards during earthquake and deficiencies may be exposed. In last decade, four devastating earthquakes of world have been occurred in India, and low to mild intensities earthquakes are shaking our land frequently. It has raised the questions about the adequacy of framed structures to resist strong motions, since many buildings suffered great damage or collapsed. A number of multi-storey car parking structures in urban India are constructed at airports, railway stations, etc. in regular and irregular shape for architectural, aesthetic or economic reasons to reduce the problem of parking. The materials being used for the structures may be having same properties and in some times it may vary in strength, mass etc. To evaluate the performance of framed buildings under future expected earthquakes, a non-linear static pushover analysis has been conducted on a typical multi-storey car parking structure. To achieve this objective, a 3D framed multi storey car parking structure (G+3) is modeled in SAP 2000 in which the structure is open in all stories with rigid floors. Such features are highly undesirable in buildings built in seismically active areas because of lesser mass of the structures, this has been verified in numerous experiences of strong shaking during the past earthquakes. We are investigating the effect of strength irregularities in the present multi-storey car parking structure of R/C frames on the seismic performance using nonlinear static push-over analysis based on computational models. From output non-linear analysis, we compare the Base shear and Displacement occurs in different strength irregularities for the different load combinations in seismic zone IV.