MODIFICATION OF PORTAL METHOD FOR ANALYZING THE FRAMES

Abstract

The portal method is one of the common approximate methods in the analysis of statically indeterminate structures. This method is used to analyze the frames which subjected to lateral loadings such as wind, earthquake, and blast loadings. The portal method is still used in the planning phase of projects, preliminary designs, and quick checking for analysis. In this paper an improvement is presented to make the portal method analysis more closer to the accurate analysis for one bay frames. In this work, the analysis by using the finite element method is carried out for a twenty seven building frames with various numbers of bays and stories. The outputs indicate that some improvements in the portal method will be useful to make this method more accurate. The improvements have been written in a new "modified portal method". In order to compare the results of the analysis after improvement, a typical five frames have been analyzed by using three methods: namely, portal method, modified portal method (presented in this paper), and the finite element method via SAP2000 V14.