SEISMIC VULNERABILITY OF HIGHWAY BRIDGES IN DKI JAKARTA

• Main Author: MAWAR OKTAVINA, SEKAR
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/24246
• Institution: Institut Teknologi Bandung

Indonesia is an earthquake-prone country due to its geographical location, which <br /> <br /> <br /> <br /> is surrounded by active tectonic plates. Many earthquake occurrences in the past <br /> <br /> <br /> <br /> had caused thousands of casualties, thousands of collapsed infrastructures and <br /> <br /> <br /> <br /> trillions rupiahs of economic loss. Through these experiences, it is clear that <br /> <br /> <br /> <br /> Indonesia must have an adequate prevention and mitigation plan towards <br /> <br /> <br /> <br /> earthquake disasters so that the risk can be reduced. The major objective of <br /> <br /> <br /> <br /> earthquake disaster risk reduction is to minimalize the fatalities due to earthquake <br /> <br /> <br /> <br /> occurrence. However, fatalities are not caused by the earthquake occurrence <br /> <br /> <br /> <br /> directly, but are caused by collapsed infrastructures which could harm the <br /> <br /> <br /> <br /> surrounding people. Therefore, it is important to assess the vulnerability of <br /> <br /> <br /> <br /> infrastructures due to earthquake to prevent fatalities. <br /> <br /> <br /> <br /> DKI Jakarta as the capital city of Indonesia holds important socio-economic <br /> <br /> <br /> <br /> activities that cover both nationally and internationally. Many infrastructures are <br /> <br /> <br /> <br /> built in DKI Jakarta to support those activities despite the fact that DKI Jakarta is <br /> <br /> <br /> <br /> also a potential seismic hazard area. Seismic vulnerability assessment of all <br /> <br /> <br /> <br /> infrastructures is important to be conducted, however only buildings have been <br /> <br /> <br /> <br /> done while highway bridges have not. Therefore, seismic vulnerability of highway <br /> <br /> <br /> <br /> bridges in DKI Jakarta is necessary to be assessed to prevent earthquake disaster. <br /> <br /> <br /> <br /> The seismic vulnerability is accounted from fragility curve developed by HAZUS <br /> <br /> <br /> <br /> under current seismic demand of DKI Jakarta. Though it is addressed for <br /> <br /> <br /> <br /> buildings, it will be used as an approach for highway bridges with several <br /> <br /> <br /> <br /> adjustments. The fragility curve is a useful tool to describe how vulnerable a <br /> <br /> <br /> <br /> bridge to a certain magnitude of earthquake occurrence is in terms of damage state <br /> <br /> <br /> <br /> probabilities. The fragility curve is derived from highway bridge models to <br /> <br /> <br /> <br /> represent existing bridge in DKI Jakarta and its variations to the structural <br /> <br /> <br /> <br /> capacity to address all possible conditions that can affect the probabilities in the <br /> <br /> <br /> <br /> fragility curve. There will be six original models to represent existing highway <br /> <br /> <br /> <br /> bridges according to its design year. All models have typical configuration which <br /> <br /> <br /> <br /> is determined from common existing bridge structural type in DKI Jakarta. The <br /> <br /> <br /> <br /> models will be designed according to its respective loading codes, seismic codes, <br /> <br /> <br /> <br /> and design codes available in that year. The design focus in this simulation is the <br /> <br /> <br /> <br /> earthquake design since it will be different for each design year according to each <br /> <br /> <br /> <br /> iii <br /> <br /> <br /> <br /> respective seismic code. The performance of the designed models will also be <br /> <br /> <br /> <br /> evaluated under current seismic demand using pushover analysis. <br /> <br /> <br /> <br /> The study shows that, (1) the newer the codes the more stringent seismic detailing <br /> <br /> <br /> <br /> and design that it requires, (2) all models have performance levels in Immediate <br /> <br /> <br /> <br /> Occupancy (IO) and Life Safety (LS) range under current seismic demand which <br /> <br /> <br /> <br /> indicates that all highway bridges are strong and ductile enough to resist the <br /> <br /> <br /> <br /> earthquake forces, (3) the steeper the slope of the fragility curves the more <br /> <br /> <br /> <br /> vulnerable the highway bridges to a certain damage state at given Sd value, (4) the <br /> <br /> <br /> <br /> more ductile the bridge the less vulnerable it is to a certain damage state, (5) <br /> <br /> <br /> <br /> overall, existing highway bridges in DKI Jakarta are not too vulnerable to current <br /> <br /> <br /> <br /> seismic demand since the target performance level of life safety or less is more <br /> <br /> <br /> <br /> likely to happen.