- 學位論文
新高強度鋼筋混凝土柱與鋼梁接頭承壓行為研究
Joint Bearing Behavior of New High-Strength Reinforced Concrete Columns and Steel Beams
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摘要
本研究旨在探討高強度鋼筋混凝土柱與鋼梁複合結構 (New RCS) 之梁柱接頭承壓強度設計方法。已知RCS梁貫穿型接頭傳力行為中，承壓破壞為接頭區上下受鋼梁翼板擠壓所導致之混凝土壓碎破壞，是一種控制接頭破壞模式的行為，而承壓強度與鋼筋混凝土斷面之彎矩強度計算概念相似，不同的是混凝土壓應力僅作用於翼板寬度範圍內，因此理論上應將軸力參數納入接頭承壓強度之計算，然而既有的RCS設計規範中接頭承壓強度之評估方法皆未考慮到軸壓的影響。 本研究欲將New RC材料用於RCS中，以期發展為可承受更高軸力之New RCS結構，因此針對「高強度」鋼筋混凝土柱與鋼梁接頭設計為接頭承壓破壞，並施以「一高一低之軸壓比」。本研究採用實驗研究法，由New RCS梁柱接頭試體反復載重試驗之分析結果，探討高軸力對接頭承壓強度是否具有影響力。此外，本研究欲以試驗結果驗證所提出New RCS梁貫穿型接頭承壓強度設計方法，考量到不同軸力下中性軸相應之移動，將能呈現出低軸力與高軸力下接頭承壓強度的差異。 依據研究目的共設計兩座大尺寸New RCS梁貫穿型外部接頭試體，於試驗中分別施加 之相對低軸力與 之相對高軸力，並保持其餘設計參數之一致性。接頭試體設有橫向梁且銲接於直通梁上，其接頭區與鋼筋混凝土柱之橫向圍束皆使用五螺箍筋，且有配置用以圍束接頭區混凝土之承壓面板及補強翼板在主筋穿過位置開孔之蓋板。本研究之反復載重試驗採用推梁不推柱之加載方式，以梁反曲點位移控制試驗進行，藉由分析試驗過程中測得之數據資料，探討New RCS接頭承壓強度預估之準確性。 試驗結果顯示本研究所使用之New RCS接頭設計方法可保守預估接頭承壓強度，低軸力與高軸力下試體皆能遠超過預期承壓強度後發生破壞；由試體破壞模式之差異判斷軸力對接頭承壓強度具有影響力，且研究中所設計之高軸壓比有提升承壓強度之效應；亦驗證所提出考慮軸力影響之接頭承壓強度設計方法可反映出試體實際破壞模式，然而高軸壓比之試體其最大強度非由預期破壞模式控制，無法確認在高軸力下承壓強度預估之準確性，故本研究建議沿用可保守預測承壓強度且不考慮軸力影響之RCS接頭設計方法。
並列摘要
This study aims to ensure the design method of the joint bearing strength for high-strength reinforced concrete columns and steel beams composite structures (New RCS). It is known that in the mechanism of force transmission of RCS beam-through type joints, bearing failure is caused by the crushing of concrete due to the compression of the steel beam flanges in the bearing area, which is one of the controlling failure modes of joints. The calculation concept of the joint bearing strength is similar to the strength of reinforced concrete section. The difference is that the concrete compressive stress is only applied within the range of the steel flange width. Theoretically, the axial force would be one of the parameters in the calculation of joint bearing strength. However, the existing RCS joint design codes do not take the effect of axial force on the bearing strength into account. This study intends to develop New RCS structures that can withstand higher axial forces, and adopts experimental research methods by performing cyclic tests of beam-column joint specimens. In this study, two of "high-strength" reinforced concrete column and steel beam joints are designed to suffer joint bearing failure, and are applied with "high axial compression ratio and low axial compression ratio". From experimental analysis and results of cyclic tests, this study will find out whether high axial forces have an impact on joint bearing strength. In addition, this study will verify the proposed New RCS design method of joint bearing strength, in which the moving of neutral axis is corresponding to different axial forces. Thus, this new method will show the difference of joint bearing strength under low and high axial forces. According to the research objectives, two large-scale specimens of New RCS external beam-through type joints are designed, which are applied with of axial compression ratio and relatively high one in the test, while maintaining the consistency of other design parameters. The transverse confinement of the joint and the reinforced concrete column are made of multi-spiral reinforcement. The specimens were fixed by pin fixtures at the two ends of New RC column and applied with cyclic loadings on the inflection point of beam. The loading process was controlled by inflection point’s displacement of beam. With the data obtained during the test, the accuracy of the joint bearing strength of New RCS joints could be verified. The test results showed that the design method of New RCS joints used in this study can conservatively estimate the joint bearing strength. The specimens under low and high axial forces can far exceed the expected bearing strength. Since the failure modes of two specimens were different, it shows that axial force has an impact on the joint bearing strength and the specimen with high axial compression ratio in this study has stronger bearing strength than the other one. It also verifies that the proposed design method of joint bearing strength, which takes the influence of axial force into account, can reflect the actual failure mode of the specimen. However, the maximum strength of the specimens with higher axial force is controlled by unexpected failure, and it cannot be confirmed the actual bearing strength under high axial force. Therefore, the study still suggests that the bearing strength design method of New RCS joint should use the existing design method for RCS joints, since it can conservatively predict joint bearing strength within the normal axial compression ratio.
參考文獻
[1] 王威儒 (2020)。高強度鋼筋混凝土柱與鋼梁貫穿型接頭耐震行為。國立臺灣大學土木工程學研究所，臺北市。
[2] 賴柏丞 (2021)。高強度鋼筋混凝土柱與鋼梁接頭耐震行為—五螺箍筋。國立臺灣大學土木工程學研究所，臺北市。
[3] 李宗軒 (2021)。高強度鋼筋混凝土柱與鋼梁接頭耐震行為：直線型箍筋。國立臺灣大學土木工程學研究所，臺北市。
[4] 汪暐倫 (2022)。高強度鋼筋混凝土圓柱與鋼梁接頭耐震行為。國立臺灣大學土木工程學研究所，臺北市。
[5] Deierlein, G.G., Parra-Montesinos, G.J., Cordova, P.P., Bracci, J.M., & Kanno, R. (2015). DRAFT - Pre-Standard for the Design of Moment Connections between Steel Beams and Concrete Columns. Appendix to John A. Blume Earthquake Engineering Technical Report 189. Stanford Digital Repository.