SEISMIC PERFORMANCE EVALUATION OF RC BUILDINGS DESIGNED AS PER BCP-2007 AND BCP-2021

Abstract

Pakistan is still striving for improvements in construction industry. Major construction in private sector is carried out as non-engineered; there are very few projects that are properly designed for gravity and lateral loads, which is main cause behind deaths in major earthquakes. For example, Kashmir-Hazara (2005) earthquake caused deaths of 85,000 people. Nevertheless, after the Kashmir-Hazara (2005) earthquake, the government and engineering commission stressed on execution of a seismic code and introduced Seismic Provisions of Building Code of Pakistan-2007. The same building code of BCP-2007 was being used till 2021 but now the government has introduced a new building code known as Building Code of Pakistan-2021. The major change that is adopted in new building is the change in seismic hazard parameter that is changed from peak ground Acceleration (PGA) to spectral Acceleration. In previous code based on PGA values the whole country was divided into five zones whereas the new code gives short and long period acceleration for each city. The concept of risk category is introduced in the new building code which is utilized to find the seismic design category which is a new concept that was not there in the previous code these changes will change the construction industry and these changes need to be addressed by comparing design of both the codes Three sample buildings were selected 4, 8 and 13 Storey. All three building were moment resisting frames which is a common practice in Islamabad. Our study is focused for the region of Islamabad. For the analysis of all three structure both BCP-2007 and BCP-2021 were utilized. Comparison of global and local responses was being made as per the load pattern of BCP-2007 And BCP-2021 the responses were more for the later code. Further by utilizing the design actions as per both codes, All the three buildings were designed. After designing the comparison of the quantities was made for all three structures that were designed as per both codes, quantities as per BCP-2021 were more. 9 8 storey structure was selected as representative building for non-linear seismic performance assessment. For this non-linear static pushover analysis was performed for both the designs that were as per BCP-2007 and BCP-2021. After doing Push-over analysis of these structures results showed weak behavior of BCP- 2007 design which was quantified using the backbone curves of these structures.