阿緱城門震害扶正修復與經驗探討

A Study of the Shoring Back Method for the Earthquake Damaged Agou City Gate

阿緱城門拱腹與拱券介面在地震作用下產生錯移，2009年修復時針對此錯移損壞採扶正工法。工法過程包含施力概估、保護措施、施力鋼架及千斤頂安裝、量測儀器裝置、扶正加載過程記錄、以及扶正後加固與修復等。本案為國內古城門修復採扶正工法之首例，其過程經驗值得作為後續類似修復問題之參考。本文之探討顯示，扶正施力經由結構分析軟體適當模擬所需施載力為5521.5kgf，此與修正後之實際加載4335.8kgf大致相近。另外檢討本案工法過程，顯示扶正規劃時位移計之數量若能增加，加載操控方式若能改善，記錄結果將更為正確完整；而施載前本體之保護以及扶正後必要加固，亦關係整體扶正修復成果，必須在修復書圖中做詳細規範。

The existing Agou ancient city gate suffered damage in the 2006 Hen-choon earthquake. In this earthquake, the upper masonry wall of the west side slid about 2cm with respect to the lower gate vault. To repair this damage, shoring back was suggested by the restoration reviewing committee. This is the fi rst known project to adopt this method for ancient gate restoration in Taiwan and the experience obtained is valuable for future restoration of heritage architecture. In this study we use fi nite element analysis to simulate the part to be shored back and evaluate the force required. The calculated force is 5521kgf, which is close to the actual load applied. In this case, we also found that if the number of displacement transducers could be increased, the recording obtained would be more accurate. In addition the protection of masonry work prior to shoring as well as strengthening it after shoring, which is closely related shoring restoration, need to be specifi cally provided in the restoration drawings and specifi cations.