Application of BCP-2007 and UBC-97 in seismic vulnerability assessment of gravity designed RC buildings in Pakistan

Recent earthquakes in Pakistan (Kashmir 2005, Balochistan 2008, and Balochistan 2013) revealed the vulnerability of existing building stock and the deficiencies in the then prevalent Pakistan Seismic Code (PSC-86 (1986)). This study investigates, through an analytical framework, the seismic vulnerability of these and other such buildings, in accordance with the newly developed Building Code of Pakistan - Seismic Provisions 2007 (BCP-SP 07). Detailed failure mode is presented for buildings designed as per the new code. Collapse of structures is predicted for only 8% increase in PGA after moderate damage. A previously developed method, based on Eurocode-8 (2004), is used as baseline. A deficient reinforced concrete frame, typical to local building practices, is analyzed and assessed for vulnerability using the BCP-SP 07 (2007) framework. A comparison is drawn for the same building, based on Eurocode-8 (2004). Derived vulnerability curves show that the previous framework overestimated the damage and hence the vulnerability. Comparison of vulnerability parameters with previous studies show slight difference in performance of buildings.