國中小校舍結構材料強度選用對耐震能力評估之影響

近年來國家地震工程研究中心，為致力於提升老舊校舍的耐震能力，以防止校舍建築未來於大地震侵襲時發生無預警之倒塌而造成學生傷亡，因而發展結構物側推分析方法用以進行耐震評估，此法已引起國內學界甚多之論著討論，多面向地探討老舊校舍之耐震能力。惟對材料之取樣試驗進而選用其強度，其選用強度之精確度對耐震能力評估之影響如何？又，該材料強度變化與結構型式變化對耐震能力評估之關聯性如何？甚值探討。本文研究係依側推分析之結果予以迴歸分析之方式，進行探討數種常見國中小校舍型式之耐震能力，亦即以各種不同高寬比、長寬比之校舍，於混凝土及鋼筋材料強度變化下分析探討其耐震能力之關聯性。分析結果顯示：耐震性能與材料強度及結構特性之間呈現高度相關性，應可藉由該關係曲線推估老舊校舍耐震性能隨材料強度增減之變化，俾迅速了解並提供實務評估與判斷之參考。

關鍵字

側推分析；耐震性能；迴歸分析；材料強度

並列摘要

In recent years, the National Center for Research on Earthquake Engineering (NCREE) endeavors to enhance the seismic resistance capacity of old buildings in campuses, which aims to prevent buildings' collapse without pre-warning and to reduce casualties during earthquakes. There are considerable research articles to explore the seismic resistance capacity of old buildings in campuses from various aspects. However, few papers have discussed the mechanism of choosing the material strength from testing samples, and how materials' strength affects the results of assessment of seismic resistance capacities of buildings? Furthermore, some other issues shall be tackled as well, such as what are the interaction effects of materials' strength and structure types on the assessment of seismic resistance capacity of buildings? Those are important research issues. Hence, we construct a model to assess the seismic resistance capacities of buildings with regression analysis and the NCREE pushover analysis theory, by considering various height-width ratios of buildings, length-width ratio of buildings, and material strength of concrete and reinforcement in several common types of structure of buildings in campuses. The results showed that seismic resistance capacities of buildings have high correlation between material properties and structure types of buildings. We establish some curves, which may use to estimate the seismic resistance capacities of buildings. These results can provide practitioners for decision-making in analyzing the seismic resistance capacities of buildings in campuses.