-..EFFECT OF SETTLEMENT OF FOUNDATION INCLUDING SEQUENTIAL CONSTRUCTION OF MULTISTOREYED FRAMES

Abstract

Growing pressure on land has given impetus to incorporation of multistoreyed buildings particular-ly in urban planning and layout, With this trend of ver1..coi growth, lot of . efforts have been directed t.otir- ards analysis and design of multistoreyed buildings throughout the world. Various classical methods,like moment distri-bution, slope deflection and Kani's method have been used for analysis of multistoreyed buildings.. In recent years, however, stiffness and finite element. method of analysis have come to the fore with the advent of increased digital computer facilities. The stiffness method takes care of axial deformation of the members, which are quite considerable in case of multistoreyed buildings. Multistoreyed building frames are usually analysed by the conventional one stop method consider-ing their bases to be either completely fixed or hinged. However, the foundation, resting on defor-mable soil, also undergoes deformation depending on the relative rigidities of the foundation, the -ruper- structure and the soil. Following the. mode of cons-truction., it becomes clear that the self weight of beams, columns, slabs and finishing items are applied 2 in sequence at different stages of construction and reu.oval of shuttering, where as other loads like live load and wind load or seismic load are applied after completion of the structure. Unfortunately very less work has been done in analysis of multistoreyod buil-ding taking simulation of s iquence of -construction and their bases as deformable. Multistoreyed frames are analysed for moment, shear and axial forces with or without combination of dead, live load and wind load or seismic load for getting the critical design values. The stress resultants that are obtained on the above simplifying assumption of single step analysis founda-tion as fixed or hinged are different from the stress resultants which actually exist because- of the s,aquen- tia]. incidence of part of the dead load and foundation as deformable. Sequential and Interactive analysis is therefore necessary for- correctly assessing the mem-ber forces in the superstructure...