LATERAL LOAD ANALYSIS OF ASYMMETRIC MULTISTOREYED BUILDINGS

Abstract

The rapid growth of the urban population and the consequent pressure on limited space have considerably influenced city residential development. The high cost of the land, the desire to avoid a continuous urban sprawl and the need to preserve important agricultural production, have all contributed to drive residential as well as commercial buildings upward. Further, due to optimal use of land, Architects and Engineers were forced to adopt the shape of building, which is not symmetrical. Discontinuities in strength and stiffness of the components of the structure, and set back form of structure, also leads to asymmetry in a building. In contrast to vertical loads, the effect of lateral load on buildings are quite variable and increases rapidly with the increases in height. The structural system, which is considered in this study is wall-frame structure. The interacting wall-frame combination is appropriate for buildings in the 40 to 60 storeys range, well beyond that of rigid frames or shear walls alone. Though finite-element 3-D analysis of tall buildings is available but its practical use is rather limited because of the enormous requirement of computer storage and computation time. Thus, to find a basis for preliminary sizing of member and to get a quick evaluation of alternative structural schemes from which one may select the most appropriate structure for detailed study, approximate analysis have been proved to be quite useful. This dissertation deals with the approximate analysis of the distributkin of lateral forces among the components of the three dimensional asymmetric multistoreyed buildings. Two buildings have been considered for analysis. Building-1 is considered for the comparison of results because, for this structure, exact analysis have already been done by many investigators and further, horizontal force interaction in asymmetric form of buildings, which twists, have been studied.