| dc.description.abstract | This research aims at collecting relevant data for the bridges which were damaged by typhoon Morakot that hit Taiwan in August, 2009, such as satellite photos, geographical pictures and maps, including rivers and land-sliding areas near by the damaged bridges. All the above data, along with basic bridge structural data, levels and volumes of water current, and data of rainfalls, were integrated by a geographical information system to investigate the vulnerability factors for the damaged bridges. Five vulnerability factors were concluded: (1) Type I: Impacts of debris flows, (2) Type II: Massive currents and floods, (3) Type III: Bridge located at the waterway front, (4) Type IV: Land slides near bridges, and (5) Type V: Scouring of pier foundations. Among these factors, Type I and II were the most common factors for which bridges were damages. Thus, critical boundary lines of rainfalls were drawn for future reference based on the rainfalls due to typhoon Morakot and other historical typhoons.
This research also investigates proper bridge management and maintenance mechanisms for various phases when disasters occur. Before a disaster occurs, the most important tasks are preparation and reinforcement of vulnerable bridges; when the disaster occurring, monitoring of structural components and nearby environments become critical; and after the disaster occurs, construction of temporary bridges and planning of alternative routes are crucial.
Results of this research can be concluded as (1) collecting of relevant data for damaged bridges, (2) analyzing vulnerability factors, (3) analyzing critical boundary lines of rainfalls, and (4) proposing proper mechanisms. Findings of this research should be helpful to the reconstruction of damaged bridges and to future disaster prevention efforts.
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