SEISMIC PERFORMANCE OF SULTAN AZLAN SHAH BRIDGE IN PERAK UNDER LOW EARTHQUAKE GROUND MOTION

In recent years, Malaysia is more aware of the seismic effect on their structures because the tremors were repeatedly felt over the centuries from the earthquake events around Malaysia. Most bridges in Malaysia do not take earthquake loadings into structural design consideration. Therefore the seismic structural vulnerability is very important in order to recognize the performance of the bridges. The seismic analysis for bridges will be conducted as linear and nonlinear problems. In this analysis, Sultan Azlan Shah Bridge in Perak which consists of 5 spans (360 meters) was modeled using two dimensional and three dimensional concepts. The site specific analysis will be performed to determine the earthquake loading (e.g. surface time history and design response spectrum) using borehole data. Design response spectrum will be constructed using IBC2000 modification. The seismic analyses conducted were vibration analysis, time history analysis, response spectrum analysis and damage inelastic analysis. Free vibration analysis presented the periods and mode shapes of the structure while time history and response spectrum analyses considered the applied forces on the deck and piers. Damage inelastic analysis showed the critical part of the bridge structural failure under several peak ground accelerations (PGA). It can be concluded that Sultan Azlan Shah Bridge is safe under earthquake loading when subjected to local site effect of surface acceleration at 0.161g. The bridge started to show initial cracking at 0.25g and collapsed at 0.32g.