COMPARATIVE STUDY ON RC FRAME DISPLACEMENT DUE TO EARTHQUAKE FORCE BASED ON BNBC 2006 & BNBC 2015

Abstract

The study was carried to have a Comparative study on the displacement of structures of specific areas’ due to earthquake forces based on both the code BNBC 2006 and proposed BNBC 2015. Three dimensional modeling of the structures was generated using ETABS software (version 2009). By comparing BNBC 2006 and 2015, a specific area of Bangladesh could be in different seismic zones with different co-efficient. In that context some cases (case 1 to case 6) have been idealized to understand the variation in structural response due to the changes in codes. For all the cases the structures are displaced more for BNBC 2015 considerations rather than BNBC 2006. The column sizes and orientations are applied considering the base shear of respective structure. The analysis based on BNBC 2015 showed that, the displacements of 5 storied structures significantly low for the most critical condition case 1 and by this understanding 5 story is not considered for the other cases. Except for case 1, the 10 storied structures are within allowable limit for other cases but the increments of top displacement are considerably high in case 3 and case 5. The 15 storied building exceed the allowable displacement limit at the height of approximately 80ft, 105ft and 115ft for case 1, case 2 and case 3 respectively. For case 4, case 5 and case 6 the structural displacement of 15 storied buildings are within allowable limit for BNBC 2015 also. The analysis result indicates that the existing structures in the areas of case 1, 2 and 3, as mentioned in methodology, may require intense assessments considering the new BNBC code. The increment in top displacements for the cases 4, 5 and 6 are considerable high, whatsoever the top displacements are within allowable limit for all the cases. In this context the structures in the areas of cases 4, 5 and 6 may also require assessments for compliance consideration.