臺灣逾40%之橋梁為須常維修之老舊橋梁，又因全球氣候變遷致使極端氣候發生頻率與強度皆倍增，橋梁受災而損壞或倒塌之可能亦隨之增加。若橋梁受災損壞或中斷後，為了恢復交通重建橋梁有其必要性。但不論重建或新建橋梁，皆應考量複合性災害之不利影響。 本研究以主要造成橋梁災害如洪流沖刷、土石流與地震之複合性影響為核心，探討此複合性災害對橋梁之影響。本研究首先初步彙整洪流沖刷災害、土石流災害以及與地震災害之影響因素、模式與程度，並製成專家問卷後進行專家訪談，以確認各因素之適切性並加以分級。本研究利用ArcGIS進行災害潛勢分析，首先蒐集所需之圖資，接著利用地資訊處理功能將個別災害分級，再將所有圖層套疊後，以本研究所擬定之複合性災害評估流程，將高災害潛勢區域排除，以評選出相對安全之可能建橋區域。本研究以桃園縣復興鄉雪霧鬧橋與新竹縣新豐鄉竹仔坑橋為例，進行複合性災害潛勢評估之案例分析與探討，以驗證研究成果之成效。本研究將複合性災害之潛勢分析應用於橋梁選址上，以避免橋梁再次崩壞造成安全與經濟上之損失。本研究之成果可提高橋梁工程規劃階段選址評估之效率，使橋梁工程能因應氣候變遷並實現工程永續之理想。More than forty percent of the bridges in Taiwan are considered to be old that require frequent maintenance. Extreme weather conditions due to global warming worsen the possibilities of collapse of these deteriorated old bridges. It is necessary to perform bridge reconstruction to restore traffic once a bridge collapses. However, both the reconstruction and newly construction of bridges require consideration of the adverse effects of compound disasters. This research aims at performing hazard potential analysis for selecting bridge sites considering scouring, debris flows, and earthquakes and their compound effects. A preliminary literature review was concluded before conducting a survey from bridge experts to identify factors of the disasters. Each of the factors was also classified into various degrees of danger based on its content. High hazard potential areas are excluded for site consideration on a geographical information system, ArcGIS, after overlapping layers of each disaster that have classification of areas showing various hazard potentials. This research also established typical processes for such evaluation of nearby areas of a bridge. Two local bridges were tested to demonstrate the feasibility of such evaluation. This research applies hazard potential analysis on bridge site selection considering the adverse compound effects due to scouring, debris flows, and earthquakes. The established evaluation processes avoid re-occurrence of bridge collapse after its reconstruction, thus economic loss can be reduced. Results of this research improve safety and the efficiency of bridge site selection to adapt to climate changes and to attain sustainability of bridge engineering.
