Perpustakaan Digital ITB

Indonesia is an earthquake-prone country due to its geographical location, which is surrounded by active tectonic plates. Many earthquake occurrences in the past had caused thousands of casualties, thousands of collapsed infrastructures and trillions rupiahs of economic loss. Through these experiences, it is clear that Indonesia must have an adequate prevention and mitigation plan towards earthquake disasters so that the risk can be reduced. The major objective of earthquake disaster risk reduction is to minimalize the fatalities due to earthquake occurrence. However, fatalities are not caused by the earthquake occurrence directly, but are caused by collapsed infrastructures which could harm the surrounding people. Therefore, it is important to assess the vulnerability of infrastructures due to earthquake to prevent fatalities. DKI Jakarta as the capital city of Indonesia holds important socio-economic activities that cover both nationally and internationally. Many infrastructures are built in DKI Jakarta to support those activities despite the fact that DKI Jakarta is also a potential seismic hazard area. Seismic vulnerability assessment of all infrastructures is important to be conducted, however only buildings have been done while highway bridges have not. Therefore, seismic vulnerability of highway bridges in DKI Jakarta is necessary to be assessed to prevent earthquake disaster. The seismic vulnerability is assessed from fragility curve developed by HAZUS under current seismic demand of DKI Jakarta. Though it is addressed for buildings, it will be used as an approach for highway bridges with several adjustments. The fragility curve is a useful tool to describe how vulnerable a bridge to a certain magnitude of earthquake occurrence is in terms of damage state probabilities. The fragility curve is derived from highway bridge models to represent existing bridge in DKI Jakarta and its variations to the structural capacity to address all possible conditions that can affect the probabilities in the fragility curve. There will be six original models to represent existing highway bridges according to its design year. All models have typical configuration which is determined from common existing bridge structural type in DKI Jakarta. The models will be designed according to its respective loading codes, seismic codes, and design codes available in that year. The design focus in this simulation is the earthquake design since it will be different for each design year according to each respective seismic code. The performance of the designed models will also be evaluated under current seismic demand using pushover analysis. The study shows that, (1) more stringent seismic detailing and design is required in more recent codes, (2) all models except Model II, III, and IV in X direction have performance levels in Immediate Occupancy (IO) and Life Safety (LS) range under current seismic demand; performance level of Model II, III, and IV in X direction could not be determined due to small structure capacity relative to current seismic demand, thus makes them more vulnerable than other models, (3) vulnerability assessment using fragility curve developed by HAZUS is dependent to both ?ds and median Sd damage state which describe the steepness and the range of the curve, (4) the more ductile the bridge the less vulnerable it is to a certain damage state, (5) overall, existing highway bridges in DKI Jakarta are not too vulnerable to current seismic demand since there is no significant differences occur in the fragility curve results between each bridge model.