樓版剪力強度試驗應用於外加RC構架補強

台灣目前廣泛使用之補強方法為擴柱補強、翼牆補強與剪力牆補強。若針對中高樓層建築物進行常見補強方式，恐會引起社會之反彈，原因在於常見之補強方式有共通不足處，即補強過程需將居民安置於他處，會大量增加社會之成本，故本研究針對台灣鮮少使用之外加RC構架補強方式作探討，可解決常見補強方法之不足處。本研究之補強方法為透過樓版傳遞地震力，故樓版傳遞剪力強度之容量為研究主軸，透過本研究設計之樓版剪力強度試驗，確認在樓版寬跨比小於0.375的條件下，其剪力強度僅與樓版總跨度有關、破壞模式為剪力破壞，並驗證利用規範作為樓版設計強度處於保守側。為驗證外加RC構架補強於中高樓層建築物之效益，利用套裝軟體ETABS進行非線性側推分析(詳細評估)，補強結果能有效提升耐震能力。另外並針對彎矩與軸力-彎矩兩種非線性鉸性質作探討，確認採用軸力-彎矩非線性鉸較能反映中高樓層建築物於非線性側推分析中，柱軸力有劇烈變化之情形，以避免高估耐震能力。

關鍵字

中高樓層建築物；外加RC構架補強；樓版剪力強度試驗；彎矩非線性鉸；軸力-彎矩非線性鉸

並列摘要

The retrofitting methods widely used in Taiwan are RC jacketing, adding wing wall and shear wall. If common retrofitting methods are applied to mid-to-high-rise buildings, it may cause a social opposition because the common retrofitting methods have general defects, that is, the retrofitting process requires the residents to be resettled in other places, which will greatly increase the cost of society. In view of the external RC frames rarely used in Taiwan, this research studied the retrofitting method focusly. This methods can solve the deficiencies of general retrofitting methods. The external RC frames used in this study is to transmit seismic forces through the slab. Therefore, the capacity of shear strengths of slabs is the keypoint of the study. Through the shear strength test of slabs designed in this study, it is confirmed that under the condition that the width-to-span ratio of slabs is less than 0.375, the shear strength of slabs will only be related to the total span of slabs, and the failure mode is shear failure. And the use of the specification as the design strength of slabs is on the conservative side. In order to verify that the external RC frames is benefitial to mid-to-high-rise buildings, the software ETABS was used to conduct a nonlinear pushover analysis (detailed evaluation), and this retrofitting method can effectively improve the seismic capability of buildings. In addition, the reserach was conducted on the nonlinear hinge properties of M (bending moment) and P-M (axial force-bending moment). It is confirmed that the use of P-M nonlinear hinges can reflect the situation where the axial force of the column changes drastically in the nonlinear pushover analysis of mid-to-high-rise buildings better, so as to avoid overestimating the seismic capability.