Houfeng Bridge Failure in Taiwan

Failures of bridges that span a waterway often result from scour and channel instability near the bridge foundations. The Houfeng Bridge, which crosses the Da-Chia River in central Taiwan, collapsed in the 2008 typhoon flood event. On the basis of the historical records and survey of related data just after the collapse of the bridge, a methodology for the assessment of scour depth, including long-term general scour caused by earthquake and impinging jet scour generated by a concrete encased pipeline, is illustrated in the present study. The proposed method provides reasonable estimates for various scour components, which implies that before constructing a new or rebuilding an old bridge, one should use proper methodology and formulas to evaluate the scour potential and improve the bridge design, especially for bridges that are founded around the Houfeng Bridge. This case study also highlights the important effect of long-term general scour on bridge stability. In addition, a lesson is learned from this case study regarding the importance of bridge operation.