Behaviour of soft storey buildings against base shear

One of the observed common reinforced concrete (RC) structural failures during recent earthquakes is column shear failure. When the stiffness and associated strength are abruptly reduced in a structure along the height, earthquake-induced deformations tends to concentrate at the flexible and/or weak storey. The concentration of damage in a storey leads to large deformation in vertical members. The excessive deformation in vertical members often leads to the failure of these members and the collapse of the storey. Soft/weak first stories are especially common in multi-story residential buildings in urban areas, where the first storey often is used for open space, commercial facilities or garages. Structural walls that separate residential units in levels above may be discontinued in the first storey to meet the change in use. The first-story columns during strong earthquake shaking must resist a large base shear, inevitably leading to large storey drift concentrated in that storey. Experimental and analytical experiment was planned and conducted to study the influence of brick masonry infill against the lateral loading. In this study, one third scaled frame, with centrally brick infill in the frame along loading direction has been taken for experimental investigation. Totally two frames with two columns, along loading direction and one beam with and without infill were constructed in the frame. Until the cracks developed in infill and beam column joints, the contribution of lateral loading is being carried out, the change in lateral stiffness, strength, ductility and of the framed structure due to the presence of in fills and bare frame against lateral loading is investigated using experimental and analytically.