大號主筋五螺箍柱耐震行為研究

Seismic Performance of Five-spiral Reinforced Concrete Columns with Large-diameter Longitudinal Reinforcement

李翰勛(Brandon Li)

指導教授 ： 歐昱辰

國立臺灣大學/工學院/土木工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202102962

摘要

本研究意在探討大號主筋柱的耐震行為，並進行反覆載重試驗。試體型式分為試驗的D43號主筋柱與對照的D36號主筋柱共計兩座，皆設計為五螺箍矩形柱，且兩者有大約相同的主筋鋼筋量。本研究的目的係在探討D43號主筋柱在撓曲破壞的前提下，相較於現行工程常用的D36號主筋柱在行為上的異同與表現上的優劣，並由試驗結果顯示兩者有接近且良好的韌性容量與強度發展。然而D43號主筋柱在接近極限位移時，試體強度下降較為明顯，主筋挫曲之情形也些許早於D36號主筋柱。故本研究發展出新型態主筋挫屈行為之推導公式，同時在公式中考慮到五螺箍的圍束行為與等效彈簧模型，結果顯示兩試體的挫屈行為相近。綜合比對D36號主筋柱，D43號主筋柱表現出完整的力學行為，在強度與消能上的狀況兩者差異不大。

關鍵字

RC柱 ； 大號鋼筋 ； 五螺箍筋 ； 反覆載重試驗 ； 極限位移 ； 韌性容量 ； 主筋挫屈 ； 等效箍筋勁度

並列摘要

Two full-scale five-spiral reinforced concrete columns were tested using cyclic loading to investigate their seismic performance. The test column (C43) was designed with D43 large-diameter longitudinal reinforcement (a bar diameter of 43 mm) and the control column with D36 longitudinal reinforcement (a bar diameter of 36 mm). Test results showed that both columns exhibited flexural-dominated behavior with good displacement capacities and energy dissipation. The performance difference between the two columns was not significant. A buckling model was developed to predict the buckling behavior of longitudinal bars laterally supported by five-spiral reinforcement. Based on the proposed model, buckling of longitudinal bars within the small spiral is the governing buckling behavior for both columns. Moreover, D43 bars of column C43 have a similar buckling slenderness ratio to D36 bars of column C36. These calculated results are consistent with experimental observation. Finally, for the same amount of and within the practical spacing range of five-spiral reinforcement, the calculated buckling slenderness ratio of D43 bars is similar to that of D36 bars.

並列關鍵字

reinforced concrete ； columns ； multi-spiral reinforcement ； five-spiral reinforcement ； large-diameter bars ； seismic ； cyclic test ； buckling

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