Linear Static and Dynamic Analyses of Reinforced Concrete Spherical Dome Structure Under Seismic Loads

Abstract

Shells and spatial structures are adopted for construction of large span structures where large column-free area needs to be covered. The structures are expected to resist against various design loads mainly through their extremely strong capability which can be acquired through in-plane or membrane stress resultants and this is just the reason by which they themselves stand for external loads without columns as their structural components in the large span structures. Singly curved cylindrical shells and doubly curved spherical shells are commonly used as roofing units in civil engineering construction. The knowledge of their dynamic behaviour is important from the standpoint of analysis and design as they are subjected to dynamic loadings in their service life. In this study, the seismic behaviour of reinforced concrete spherical dome structures under static and dynamic loads is evaluated. IS: 2210-1988, Criteria for Design of RC Shell Structures and Folded plates, suggests to design shell structures for seismic loads in accordance with IS: 1893-2002, Criteria for earthquake resistant structure; however, lack in detail specifications for shell structures is to be adopted. Therefore, from this point of view, a methodology needs to be proposed for understanding the behaviour of shell structures under seismic loads. Linear static and dynamic analyses are performed on the basis of IS: 1893-2002 using SAP-2000 software. The Equivalent Static method is performed for 63 load combinations and the Response spectrum method is performed for 151 load combinations. The results shows that the spherical dome structure considered here with designed lateral force resisting system behaves well under seismic loading.