Seismic and Flood-Resistance capacity promotion and service life elongation method for existing bridge by employing Substructure Replacement Technique

摘要

Taiwan is located in Circum-Pacific seismic zone as well as the area frequentlystricken by typhoons. The exposure of river crossing bridge foundations have deterioratesharply due to the rushing rivers which cause the insufficient of seismic and floodresistancecapacity and also shorten the service life of the bridge. In order to resolve thisdangerous situation, new and creative techniques had been proposed for seismic andflood–resistance capacity promotion. Substructure Replacement Technique (SRT) descendsthe new foundation under the riverbed and the new columns smoothly connected with theoriginal pier cap. The rebuilt foundation not only strengthen the seismic capacity but alsoenlarge the waterway area, ameliorate the drainage function, improve the river landscapeand elongate the service life of the bridge. Two projects including a highway bridge and arailway bridge were discussed in this article to demonstrate the procedure and efficiencyof this technique.