本文分兩大部分，第一部分乃利用三軸拱圍束效應之Mander理論模式，分析矩形及圓形斷面短柱外部圍束材圍束時之軸向應力應變關係。第二部分乃利用第一部分所得之圍束混凝土之應力應變關係，進行柱彎矩與側向變位之預測，其中圍束材包括箍筋、FRP及鋼版。在本研究中，發展出一個程式，以Mander之三軸拱圍束模式，計算柱受不同材料圍束時之混凝土應力與應變，然後應用於柱之斷面分析，利用彎矩之曲率面積法求出補強柱之撓曲變形。 研究結果顯示，混凝土受軸壓力膨脹後，其圍束材會對其產生被動圍束，因而產生拱效應，其拱曲線可視為一抛物曲線，此抛物曲線之初始角對柱之承載能力影響很大，故在分析時應慎選拱曲線之初始角(??。利用修正Mander理論分析時，取柏桑比為0.5時，慎選適當?，可以準確預測柱軸向圍束行為，整體分析結果與實驗結果非常吻合，由分析結果得知，雙重材料圍束效果(如箍筋與FRP一起圍束)比單一材料圍束效果佳。在柱撓曲方面，本文只考慮圍束混凝土應力應變之影響，由於柱實際之撓曲變形，亦受固端旋轉及剪力變形之影響，故分析結果外力有高估現象，對於固端旋轉及剪力變形之影響有待後續研究。 There are two parts in this thesis. In first part, a triaxial confined model for evaluating the stress-strain behavior of RC short columns with external confinement is proposed. It's valid for rectangular and circular section. In the second part, by using the confined concrete stress-strain relationship in the first part, the flexural behavior of the columns is then predicted. In the study, the confining material comprises steel hoop, FRP and steel plate respectively. In this thesis, a computer program was developed to evaluate the RC columns confined with different confining materials basing on the Mender's triaxial arching confined model, by using the average stress-strain to perform the section analysis, hence apply the moment-curvature area method to the prediction of flexural behavior of columns. In the investigation of arching effect, concrete columns expend due to the axial compression, hence a passive confinement were activated, induced an arching effect, the arch curve as a parabola, and the initial angle of the parabola have a great influence in the load capacity of the columns. The arching angle of the parabola must be taken care while the analysis is performed. By using the modified Mander confined model, the poisson’s ratio of 0.5, and a suitable arching angle are selected to predict the confined behavior of the columns in a accurate way. As a result of analysis, it found that dual confinement (from hoop and FRP confinement) have a better enhancement in load bearing capacity than the single confinement. However, the experimental result did not agree with the results of flexural analysis well. This is due mainly to the influence of shear and fixed end rotation on not accounting for the prediction. The effect of the shear deformation and fixed end rotation will be followed up in the future.
