Analysis and Design of Shear Wall with Openings and Bracings in Multi-Storey Irregular Building

At present days, constructing a structure with all the regular configurations is not feasible in most of the cases due to the irregular plot dimensions, aesthetic visual and functional requirements in the urban cities. The structure with more irregular configuration either horizontally or vertically are more vulnerable to earthquake & wind forces which leads to collapse of structure, property loss and casualties. When an earthquake occurs, nearly all buildings in the area are exposed to seismic forces. When a tall structure is subjected to lateral or torsional deflections under the action of seismic loads, the resulting oscillatory movement can induce a wide range of response in the building occupants. Therefore, lateral stiffness is an important consideration in the design of multi storey structures. The improvement of reinforced concrete frame structure against lateral loading can be achieved by providing shear walls and cross bracings. In this study, a G+19 storey important service and community building with re-entrant corners has been analyzed and designed with shear wall with openings and cross bracings. Significance of shear walls and bracings has been studied with the help of nine models. This analysis and design was made as per IS 1893:2016 codal provision by using ETABS 20 software. The building models are analyzed by response spectrum method using ETABS software. The main parameters compared in this study are lateral displacement, storey drift, base shear, overturning moment and storey stiffness. Shear wall without openings shows better performance when compared to all models. Compared to bare frame, displacement is reduced by 38.6%, drift reduced by 37.6%, storey shear increased by 114.8% and storey stiffness increased to 25.6x10⁶ kN/m. Performance of building with the combination of shear wall with openings and bracings is good. Compared to bare frame, displacement is reduced by 37.2%, drift reduced by 34.4%, storey shear increased by 74% and storey stiffness increased to 19.4x10⁶ kN/m. The results of model 4 and model 9 are almost equal. Combination of shear wall with openings and bracings will helps to achieve the economy and also increases the strength