Impact of artificially seismic loading on the response of building structure in various site classifications

Abstract

The lack of local ground motion records has led to a direct adoption of El Centro accelerogram in time history technique as the most reliable method to observe structural responses. Program based simulations with respect to the provision of Indonesian standard were engaged to obtain artificial seismic accelerations for each site classification. Time history technique is utilized to analyze and compare the response of a dual system structure against seismic loadings in terms of maximum story displacement, base reaction, pier moment, story acceleration and story shear.Spectral matching process using Etabs yields better average spectral curves than using Seismomatch. This, however, relies upon the scaling method and number of iterations. Structural analysis results show that the artificial records of Lacc North, Friuli, Petrolia and Trinidad create extreme story displacement and story acceleration for site class B, C, D and E in that order. Artificial load of Friuli, Lucerne and Sylmarf yield the largest base reactions whereas maximum story shear is caused by the artificial ground motion of Chichi, Laccnorth, Petrolia and Trinidad for the ordered site classes. The average displacement at the top story of matched accelerogram or site B is 50% below the displacement by the original El Centro record while for site C the displacement reduces 10% and remains stabled in site D but increases 7% in site E. The base reaction falls about 20%–30% in site B, C and D and rises 14% in site E. Pier moment due to matched records decreases up to 6% as compared to the influence of reference record in all sites while story acceleration experienced 17% increase in site B. The artificial time history records adversely affect on the story shear response up to 51% higher than El Centro record. The result of F.TEST shows 77% difference between both techniques. The selection of correct, appropriate and sufficient ground motion records may produce ideal artificial accelerations and it is, therefore, profound to select such records since the possible difference may affect the final design of the building structure using linear time history analysis.