Comparative Study of Diagrid Structures with and without Corner Columns

Construction of multistorey building is rapidly increasing throughout the world. Advances in construction technology, materials, structural systems, analysis and design software facilitated the growth of these buildings. Recently the diagrid structural system has been widely used for tall buildings due to the structural efficiency and aesthetic potential provided by the unique geometric configuration of the system. In present work, concrete diagrid structures with and without corner columns were analysed and compared. Due to inclined columns, lateral loads are resisted by axial action of the diagonal in diagrid structure compared to buckling of vertical columns. A regular five storey RCC building with plan size 15 m 15 m located in seismic zone V is considered for analysis. STAAD. Pro software is used for modelling and analysis of structural members. Load combinations of seismic forces are considered as per IS 1893 (Part 1) 2002. Comparison of analysis results in terms of storey drift, lateral displacement, bending moment, shear forces and axial forces are presented. In diagrid structure, the major portion of lateral load is taken by external diagonal members which in turn release the lateral load in inner columns. Here, the value of axial force on interior columns for diagrid with corner column is two times more than the diagrid without corner columns. The axial force carried by the diagonal member get reduced due to the presence of corner column. Hence, the interior column has to take more axial force. Thus, the study can be concluded as the behaviour of structure without corner column is more effective than with corner columns.