ANALYSIS OF FRAME-SHEARWALL BUILDINGS UNDER STATIC AND DYNAMIC LATERAL LOADS

Abstract

The present study has been divided into two parts. In the first part of the study, the characteristics of the shear wall frame interaction under dynamic loads have been studied with the help of a 15 storeyed idealised she eer wall frame -bent. The effects of various parameters like the axial deformations of columns and shear walls, 'shear wail to column stiffness ratio,, column to bean stiffness ratio, Vpria±°ion- of stiffness of shear wall, columns and beams along height, variation of mass distribution along height' etc.* have been investigated. The dynamic force distribution obtained by modal analysis is found to depart considerably from the parabolic distribution given in I3:1893-1975; axial force is found to have significant effect on dynamic response in upper storeys. Shear deformations have significant effect on shear force distribution in lower storeys. In the second part of the study, a computer programme has been developed for static analysis for lateral loads as wells as for dynamic analysis for earthquake forces for actual shear wall frame buildings without ida a7 i- sation. An actual 14 storcyod shear wall frame building has been analysed for static lateral loads computed by the seismic coefficient method as per 15 :1893-1.975 and the some building has also been analysed by modal method. A cdmp`arison of force • and deflections computed by the modal analysis - and static analysis shows that the values computed by seismic coefficient method are very conservative mainly due to the approximate expression of time period used in IS:1893-1975.