COMPARISON OF OMAN SEISMIC CODE WITH INTERNATIONAL COUNTERPARTS BASED ON REGIONAL SEISMIC HAZARD

Oman Seismic Code (OSC) was developed in 2013 to provide guidelines for seismic analysis and design of buildings in the Sultanate of Oman. Prior to its development, specifications of Uniform Building Code 1997 (UBC) and International Building Code 2006 (IBC) were used. This study compares base shear, lateral force distribution, and effective storey drift obtained from the three seismic codes using equivalent static load and response spectrum analysis methods. Reinforced concrete buildings with 25m x 40m plan having columns at 5m spacing are used; 3-, 6-, 13- and 19- storeys are considered having height of 10m, 19m, 40m and 58m, respectively. The buildings were considered as having normal occupancy condition, resting on very dense soil (type-C). The study considered low and normal ductility classes defined by the OSC and compared Zone-1 of OSC with Zone-1 of UBC and IBC. OSC provided slightly higher values (20% - 35% higher) of base shear than IBC and UBC for the low ductility class. For the normal ductility class, it provided marginally lower (9% - 12% lower) values for 6-, 13- and 19-storey buildings while a higher value for the 3-storey building. The storey shear force and storey drift from the OSC also compared well with the international counterparts. Muscat that is Zone-1 of OSC is equivalent to Zone-1 of UBC and IBC.