鋼筋混凝土圓形柱橫向鋼筋圍束效果之探討

The confinement effectiveness of transverse reinforcement in circular reinforced concrete columns

10.6849/SE.201809_33(3).0001

李台光(Tai-Kuang Lee)；陳正誠(Cheng-Cheng Chen)

鋼筋混凝土圓形柱 ； 橫向鋼筋 ； 圍束效果 ； Circular RC Columns ； Transverse Reinforcement ； Confinement Effectiveness

結構工程

33卷3期（2018 / 09 / 01）

5 - 26

繁體中文

本研究完成8支大尺寸鋼筋混凝土圓形柱試體之反復側向載重試驗，共規劃R、S33、S17及D33等4個系列，以箍筋、繫筋總圍束力維持固定為原則，箍筋之圍束力以箍筋2倍的斷面積與標稱降伏強度之乘積計算，而對於十字型及井字型配置之繫筋，分別以1根及2根繫筋斷面積與標稱降伏強度之乘積，計算繫筋之圍束力，探討井字型及十字型等2種繫筋於圍束柱混凝土的可行性及有效性。研究結果顯示：(1)含十字型及井字型組合繫筋之鋼筋混凝土圓形柱，其耐震性能與側力方向具有某種關聯性，但並不顯著。故圓柱繫筋施工時應不需要特別旋轉或是調整十字型及井字型組合繫筋之方向或指定方向。(2)以本研究圍束力之定義，在相同總圍束力下，圓箍筋的圍束效果優於十字型及井字型配置之組合繫筋，另十字型繫筋比井字型繫筋圍束效果稍佳，組合繫筋之圓箍筋等效圍束力折減之計算，與繫筋配置形式及圍束力比有關，尚需後續進一步研究釐清。

In this study, a lateral cyclic load test was conducted on eight specimens of large-sized circular reinforced concrete (RC) columns to investigate the confinement effectiveness of circular ties and lap-spliced crossties. Totally, there are four series of specimens including R, S33, S17 and D33 constructed and tested. In single-cross crossties, the confining force of transverse reinforcement is calculated by adding the confinement effectiveness of one crosstie cross-sectional area. On the other hand, in double-cross crossties, the confining force of transverse reinforcement is calculated by adding the confinement effectiveness of two crosstie cross-sectional areas. The research results are presented as follows: (a) The seismic performance of circular RC columns with single-cross and double-cross lap-spliced crosstie correlates with the lateral loading direction. But its influence is not significant (b) The confinement effectiveness of circular tie is better than that of single-cross and double-cross lap-spliced crosstie. The reduction influence of lap-spliced crossties depends upon crosstie layout and the confinement force ratio. More details need further studies.

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