ABSTRACT
Taiwan is located in Circum-Pacific seismic zone as well as the area frequently stricken by typhoons. The exposure of river crossing bridge foundations have deteriorate sharply due to the rushing rivers which cause the insufficient of seismic and flood-resistance capacity and also shorten the service life of the bridge. In order to resolve this dangerous situation, new and creative techniques had been proposed for seismic and flood-resistance capacity promotion. Substructure Replacement Technique (SRT) descends the new foundation under the riverbed and the new columns smoothly connected with the original pier cap. The rebuilt foundation not only strengthen the seismic capacity but also enlarge the waterway area, meliorate the drainage function, improve the river landscape and elongate the service life of the bridge. Two projects including a highway bridge and a railway bridge were discussed in this article to demonstrate the procedure and efficiency of this technique.
