ANALYSIS OF SHEAR WALL FRAMED R.C. BUILDINGS

Abstract

The increase in population and the paucity of land, particularly in urban areas has compelled designers to go in for sky-scrapers. For low to medium rise buildings, the analysis and design with respect to lateral forces has generally been a process of checking the vertical load system for its ability to resist lateral forces. However, for tall buildings the vertical load resisting system is inefficient in resisting lateral forces. Hence in tall buildings of reinforced concrete, the lateral loads are commonly resisted by specially provided shear walls. For buildings having of 15 to 40 storeys, the shear wall-frame system has been found to be the most acceptable one. The present study pertains to lateral load analysis of some shear wall frame systems. It has been divided into two parts. In the first part, the lateral load acting on the three dimensional frame-shear wall structure is distributed to individual frame lines by a simplified method. In the second part, a computer program has been developed to determine the forces and deflections in various structural components, viz, beams, columns, link beams and shear walls, using stiffness matrix approach. In this method, the effect of shear deformation in is also taken into account. Two examples have been solved using the above approach. ii The first one is an unsymmetrical 15 storey building with two cases, firstly shear walls extend upto the top and secondly where they are not provided in the top 6 storeys. The second building is symmetrical with two cases, i.e., symmetrical shear walls and secondly one of the shear walls removed to introduce unsymmetry. The shears, bending moments and deflections are compared in two cases in each example. On the basis of this study, some useful conclusions are drawn.