Proceedings on International Conference on Disaster Risk Management, Dhaka, Bangladesh, January 12-14, 2019 Page | 16 A COMPARATIVE STUDY ON SEISMIC LOAD ANALYSIS BY BNBC-1993 AND BNBC-2017 Md. Mohiuddin Ahmed 1 , Subrata Roy 2 , Maqsuda Haque 3 ABSTRACT Significant changes have been introduced in BNBC 2017 with regard to analysis for seismic loads. To identify the changes in design and analysis of various structures a comparative study is necessary between existing code and the previous one. This study aims at the comparison of provisions of earthquake analysis only given in BNBC 1993 and BNBC 2017. It is found that seismic base shear of the building calculated by BNBC 2017 varies significantly from seismic base shear calculated by BNBC 1993. Finally, structural analysis and design of a typical eight-story hospital building situated in Sylhet (most severe zone) city are conducted to demonstrate the changes regarding seismic load in BNBC 2017 with respect to BNBC 1993. The basic differences in seismic base shear and maximum lateral displacement with the same number of stories using two codes are presented. The comparison in inter-story drift is also made using two codes. The analysis is made to compare the maximum reinforcement requirement for corner column and interior column design to provide a guideline to the engineer for the most economic design. Design of reinforced concrete buildings for seismic load in BNBC-2017 is relatively economic than BNBC-1993 the since the amount of reinforcement required is less in BNBC-2017. Keywords: BNBC-1993, BNBC-2017, inter-story drift, maximum lateral displacement, seismic base shear, overturning moment. Introduction Earthquake is a disastrous event that needs to be addressed in a more coordinated way. Although Bangladesh is extremely vulnerable to seismic activity, the nature and the level of this activity is yet to be defined. In Bangladesh, complete earthquake monitoring facilities are not available. The dynamic effects earthquake loads are usually analyzed as an equivalent static load in most small and moderate-sized buildings. A comparative study has been made to see the basic difference between BNBC (Bangladesh National Building Code) 1993 and BNBC 2017 regarding earthquake load only. The developed countries in North America, Europe, India regularly update their codes. Bangladesh National Building Code (BNBC-2017) has significant changes comparing to BNBC-1993. A detailed comparison between BNBC 1993 and BNBC 2017 is presented in tabular form for the seismic load analysis only. The effects of gravity load in combination with lateral loads are out of the scope of this study. For earthquake load analysis equivalent static method is implemented. The case study on a typical hospital building is performed for Sylhet city only. The results may vary for other cities of Bangladesh. However, a detailed comparison of lateral loads along with the impact on design analysis for low to medium rise buildings for Bangladesh is required. In this work, corresponding parameters of Earthquake loads found using the BNBC 1993 and BNBC 2017 codes are compared. A typical hospital building situated in Sylhet is selected for the case study to identify the changes in analysis and design with BNBC 2017 as compared to BNBC 1993. The analyses are conducted for base shear, maximum lateral displacement. For earthquake load base shear, maximum lateral displacement and inter-story drift are higher in BNBC 2017 than BNBC 1993. Design of reinforced concrete buildings for lateral load in BNBC-2017 is relatively economic than BNBC- 1993 as the amount of reinforcement requirement is less in BNBC-2017. The main objectives of this study are: Determination of the base shear, base moment, story shear and inter-story drift according to BNBC 1993 and BNBC 2017. Comparison of base shear, story shear, base moment and inter-story drifts by preparing an identical model to understand the comparison between the two codes. Analysis and design of a corner column 1 Lecturer, Dept. of Civil Engineering, University of Information Technology & Sciences, Dhaka-1212, Bangladesh. 2 Lecturer, Dept. of Civil Engineering, University of Information Technology & Sciences, Dhaka-1212, Bangladesh. 3 Lecturer, Dept. of Civil Engineering, University of Information Technology & Sciences, Dhaka-1212, Bangladesh. Email of Corresponding Author – mohiahmed22@gmail.com