以現地試驗檢核校舍結構耐震能力之初步評估

初步評估為校舍結構耐震能力篩選程序之其中一個階段，以此簡單、快速、且客觀之方法，有效縮小校舍結構耐震問題之規模。初步評估依據校舍座落之震區、校舍之用途、結構及其一樓垂直構件斷面之尺寸，估算其結構耐震之容量及需求，予以評分，由低至高，依序進入詳細評估。但是，初步評估之結果必須保守，避免耐震能力不足之校舍，因誤判而無法進入下一階段之詳細評估。不同於實驗室之試驗，現地試驗能充分反映既有校舍之特性，如材料強度、配筋細節、施工品質及基礎邊界條件等。有鑑於此，本文採用四棟校舍現地單向側推之試驗結果，從其尺寸及容量曲線（側力與側位移之關係）實測或實算校舍之極限剪力強度、單位樓地板面積之重量、基本振動週期、容許韌性容量及基本耐震性能（耐震容量及需求之比值），以現地試驗之實測或實算值為基礎，檢核耐震能力初步評估之估算值。經檢核後，四棟校舍之初步評估均屬保守，其基本耐震性能介於現地試驗之33.0至91.5%。縱然其中一棟之混凝土強度偏低、保護層厚度偏高，初步評估之方法仍屬保守。

關鍵字

校舍結構；耐震性能；初步評估；現地試驗

並列摘要

Preliminary evaluation is a screening stage for the seismic performance of existing school buildings. This method is simple, fast, objective and effective to reduce the magnitude of the problem of seismic deficiency. From the data of the seismic zone, importance factor, and dimensions of structure and its members, seismic capacity and demand of a school building can be estimated by preliminary evaluation. According to the seismic capacity and demand ratio, the priority of a school building to enter the next stage, detailed evaluation, is determined. However, preliminary evaluation should be conservative enough to avoid performance of school building being overestimated. Unlike laboratory tests of a school building, the material strength, reinforcement detailing, construction quality and foundation boundary conditions of in situ tests are realistic. In this paper, the results of in situ pushover tests of four school buildings are utilized. From the configuration and capacity curve (relationship between lateral force and lateral displacement) of the school building, the ultimate base shear, the weight per unit floor area, the fundamental vibration frequency, the allowable ductility capacity and the fundamental seismic performance (ratio of seismic capacity and demand) are found. Based on the results of the in situ tests of the four school buildings, the results of preliminary evaluation are examined. Preliminary evaluation is conservative. The fundamental seismic performances of the four school buildings from preliminary evaluation lie between 33.0 to 91.5% of those from in situ tests. Even compressive strength of concrete is quite low and the thickness of cover concrete is quite high in one of the school buildings, preliminary evaluation of that school building is still conservative.

並列關鍵字

school building ； seismic performance ； preliminary evaluation ； in-situ experiments

國際替代計量

以現地試驗檢核校舍結構耐震能力之初步評估

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