Parametric Study on Diagrid Structural System with and without Shear Walls

Abstract

Among the various lateral load resisting systems of the tall structures, diagrid structural system is a unique structural system and found effective compared to other bracing systems, which is increasingly popular from the past decades. The diagrids are perimeter structural configurations characterized by a grid of diagonal members which are involved both in gravity and in lateral load resistance. The diagrid structure ensures the overall stiffness and strength of the building only engaging the diagonal members in a purely axial behaviour and fully braces the interior gravity columns for stability only at joints of diagrid. The intermediate floors, are not laterally restrained by the global behaviour of the diagrid system, means if diagonals are continuous throughout the module height, the floors would derive a certain degree of lateral stiffness only from the flexural stiffness of the diagrids. Although diagrid system is good enough to perform well in lateral load resisting compare to other simple frame and shear wall building, we can combined the diagrid structure with shear walls for optimum design. The present study aimed to understand the behaviour of the diagrid structural system with shear walls at core. For this study a regular square plan of 30m × 30m diagrid structure considering different storey module (i.e. 4, 6, 8 & 12) with and without core Shear Walls is modelled and analyzed. For minimum displacement and drift different plan shape of shear wall are taken and one of them with optimum results is used for further analysis. Then behaviour of diagrid structure with and without shear wall along the height is also studied considering 24, 36 and 48 storey. ETABS software is used for modelling and analysis. Parameters such as inter storey drift-ratio, storey displacement, base shear and reduction in lateral load on diagrid are taken into consideration.