非定值軸力作用下含組合繫筋RC柱之耐震性能

The seismic performance of reinforced concrete columns using the lap-spliced crosstie with various axial load

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

《結構工程》 36卷2期 (2021/06) Pp. 51-72

https://doi.org/10.6849/SE.202106_36(2).0002

摘要

組合繫筋為由兩支一端為180度彎鉤另一端為直線的J形鋼筋搭接組合而成。本研究完成4座大尺寸鋼筋混凝土柱試體之反復側向載重試驗，探討非定值軸力作用下含組合繫筋RC柱之耐震性能。研究結果顯示：（1）非定值軸力作用下，使用180度彎鉤一體繫筋（兩端使用180度彎鉤之一體繫筋）之試體承受軸壓力之韌性（塑性轉角）表現最佳，使用組合繫筋之試體次之，使用傳統繫筋（一端具有135度彎鉤，而另一端為90度彎鉤之繫筋）之試體韌性表現最差；（2）不論使用組合繫筋、180度彎鉤一體繫筋或傳統繫筋之RC柱試體，承受軸拉力之韌性表現優於承受軸壓力之韌性表現；（3）僅承受軸壓力之柱，當柱軸力比小於30％時，可採用組合繫筋取代傳統繫筋；（4）建築結構內柱承受較大之軸壓力，當柱在地震過程中僅承受軸壓力，且柱軸力比大於30％時，此時使用組合繫筋不但可以合乎規範要求且施工容易；（5）當柱在地震過程中承受反復軸力（即軸壓力及軸拉力）時，一般而言此種情形之柱軸力比小於30％，此時可以採用組合繫筋取代傳統繫筋。

關鍵字

組合繫筋 ； 搭接長度 ； 軸拉力 ； RC柱 ； 耐震性能

並列摘要

A lap-spliced crosstie consists of two J-shaped steel bars (rebars) that have a straight end and an end featuring a 180° hook. In this study, the cyclic lateral load test of four large-scale reinforced concrete columns with axial force proportional to the lateral force was conducted to discuss the seismic performance of RC columns with lap-spliced crossties and investigate the axial tension load effect. The research results are presented as follows: (a) The seismic performance of the specimens that adopted lap-spliced crossties is superior to that of the specimen using conventional crossties and worse than that of the specimen using crossties featuring a 180° hook on the two ends. (b) The ductility of RC columns comprising lap-spliced crossties, crossties featuring a 180° hook on the two ends and conventional crossties under axial tension is superior to that under axial compression. (c) For RC columns under axial compression, when the axial force ratio is less than 30%, lap-spliced crossties can be used instead of conventional crossties. (d) The inner columns of the building structure are subjected to large axial compression. When the columns are only subjected to axial compression during the earthquake, and the column axial force ratio is greater than 30%, the use of lap-spliced crossties can not only meet the ACI design requirements, but also facilitate the construction. (e) When the columns are subjected to repeated axial forces (axial compression and axial tension) during the earthquake, generally speaking, the column axial force ratio in this case is less than 30%. In this case, lap-spliced crossties can be used to replace conventional crossties.

並列關鍵字

lap-spliced crosstie ； lap splice length ； axial tension ； RC columns ； seismic performance

參考文獻

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