Authors:
Sanjivan Mahadik; Sariputta Bhagat;
Abstract:
Shear wall is a member provided in a structure for resisting horizontal forces acting on buildings arising from wind or earthquake. It generally spans from foundation to top and is located at any position in building plan. In most of the cases shear walls are of reinforced concrete for tall buildings but these may be of timber, steel, concrete etc. for some situations and for medium or low height buildings. According to aspect ratio (length to width ratio) these are classified in to two type viz. long (slender) shear wall and short wall (squat) shear wall. Bending is predominant in long walls so long walls are designed for flexure, whereas shear is predominant in short wall so short walls are designed for shear. Shear walls are generally used in almost all buildings located at earthquake prone areas. Although it is true that shear wall effectively resist lateral forces, many shear walled buildings worldwide has collapsed during strong earthquakes occurred in recent past. After taking every care in design of buildings as per seismic resistant criteria of design given in Codal provisions, there are chances of destruction to the buildings even it is constructed with shear walls in it. To address this problem of shear wall failure, in present study the use of concealed diagonal reinforced concrete stiffeners and diagonal steel tube stiffeners were verified with the help of analysis as well as experiments to see improvement of its performance. Behaviour of squat reinforced concrete solid shear wall using conventional reinforcement, solid shear wall strengthened with inbuilt reinforced concrete stiffeners and solid shear walls using steel tube stiffener was studied with experiments and results were validated using FE software ANSYS 18.2. SOLID65 element was used to model concrete and steel reinforcement was modeled with element BEAM188. Six 1:3 scaled shear wall models of size 1000mm x 1000mm x 100mm were tested to know shear wall behaviour using concealed stiffener and to know the improvement over normal reinforced concrete walls. A significant improvement was observed in deformation capacity, strain carrying capacity as well as load carrying and of shear walls using concealed stiffeners. The concealed stiffeners will provide a better and economical solution for improving shear wall performance under lateral loading conditions.
Keywords:
shear wall, nominal strength, analysis, stiffeners, strain, ANSYS.