Investigation of Column-to-Floor Ratio for Seismic Safety of RC School Buildings in Taiwan

臺灣地理位置特殊，時有地震發生，而歷年災損報告均指出中小學校舍往往為強震下受損最為嚴重的建築群。深入了解校舍受損嚴重之原因，發現其多數呈一長排相連之樣式，此方向抵抗側力之牆量稀少，又柱設計常屬非韌性配筋，導致校舍受地震下之破壞模式常為一樓沿長向之短柱剪力破壞。 針對上述缺失，教育部於民國98年開始實施「加速高中職及國中小老舊校舍補強整建計畫」，並委託國家地震工程研究中心提供技術與行政支援。至民國100年4月已透過工作承攬者完成上傳共4518棟校舍之詳細評估結果，這些資料已納入國震中心之校舍耐震資料庫內。因此，本文藉由整理詳細評估資料庫的大量分析數據，篩選結構材料、系統與型式相近之老舊典型校舍，以統計迴歸直接找尋垂直構材量與校舍耐震性能之線性關係，以及探討樓層數等變因對耐震性能之影響。藉由統計研究，可定義校舍之安全柱量比，而柱量比係指一樓柱總斷面積和相對於二樓以上總樓地板面積之比值。在分析含磚牆構架校舍之後，亦可將磚牆斷面積轉換成相同抵抗剪力強度之等值柱量。最後本研究建議一快速保守之校舍耐震能力初步診斷公式，同時將建議之安全柱量比與相關文獻作驗證比較。Because of the special geographical location in Taiwan, the earthquake occurred frequently, and some of serious cases like Chi-Chi Earthquake caused school buildings to suffer severe damage or collapse. In depth study for the reasons of damage, the classes were connected to the style of a long row which made the walls were too few to resist the lateral force. Otherwise, the column detailing often used non-ductile reinforced design. They all led the first floor of short columns to fail in shear failure along long row direction under earthquake. Due to aforemetioned reason, the Ministry of Education commissioned National Center for Research on Earthquake Engineering (NCREE) to propose a procedure for enhancing the seismic capacities of school buildings. From 2009 to 2011 April, it had been uploaded by structural engineers to complete 4518 cases of seismic detailed assessment for school buildings. Therefore, this research organized a large amount of accurate analysis in the database, screening the resembling of structural materials, system type for the RC school buildings, then finding their linear correlation by statistical regression between seismic performance and the vertical structural member’s amounts by defined column-to-floor ratio as the ratio of the total area of column at first floor to the total floor area above first floor. Besides, this research also considered the other influences of seismic capacity. For the brick wall contained structures, its amount can be transferred to the columns under the same shear strength, and then used this relationship to discuss with the seismic performance of school buildings. Finally the main results obtained in this research gave a rapid preliminary assessment formula of seismic capacity for the RC schools buildings, furthermore recommended the column-to-floor ratio for seismic safety in each region of Taiwan, and verified with recent research