| Summary: | 碩士 === 國立臺北科技大學 === 土木與防災研究所 === 102 === Most of old buildings in Taiwan are lack of seismic resistance and thus are vulnerable to a severe earthquake. Hence, the seismic retrofit of existing buildings with inadequate seismic resistance is of urgent need. In this study, an original RC column and its two strengthened specimens, where one is a RC jacketing column and the other is a column with installing wing walls, were tested in this study. The original column with low strength concrete was designed to comply with old design standards and thus the usual detailing deficiencies in existing buildings can be simulated.
In this paper, the low strength RC columns were seismically retrofitted and cyclically tested. Test results reveal that either the column jacketing or wing walls can effectively increase the lateral shear strength. In addition, The RC jacketing can have a better improvement in capability of energy dissipation and in ductility when compared to installing wing walls. RC jacketing not only increases moment and shear capacity but also results in a flexural failure mode. Thus, the ductility increases. On the other hand, although RC wing walls can increase shear capacity, the original column and the wing walls cannot be integrated together and experience shear failure independently. After yielding the maximum lateral strength, the stiffness and strength are rapidly degraded and thus the specimen results in poor ductility. Apparently, the hysteretic loops can be classified as a typical failure mode, where stiffness degrading and strength degrading in addition to pinching are found.
|
|---|
