短柱型破坏的型钢混凝土-混凝土转换柱剪切受力性能研究

型钢混凝土-混凝土(SRC-RC)转换柱容易产生"短柱型"剪切破坏,此类剪切破坏类似于钢筋混凝土短柱的剪切破坏,剪切斜裂缝贯通整个钢筋混凝土部分。以7个SRC-RC转换柱试件和2个钢筋混凝土对比试件的低周反复荷载试验为基础,建立了受力模型用于分析"短柱型"剪切破坏形态和机理以及产生此类破坏的内在因素。产生"短柱型"剪切破坏转换柱试件的滞回曲线呈现倒S形,"捏拢"现象明显,刚度随着循环次数的增加退化迅速。采用箍筋加密措施能够有效改善转换柱的抗震性能,使其表现出较钢筋混凝土柱更好的抗剪承载力和延性。

STUDY ON SHEAR PERFORMANCE OF SRC-RC TRANSFER COLUMN WITH SHORT COLUMN FAILURE PATTERN

Shear failure occurs easily on SRC-RC transfer columns,which looks like failure pattern of short RC column,shear crack runs through the whole reinforced concrete.Shear pattern and failure mechanism are analyzed based on established shear model of SRC-RC transfer column which comes from 9 specimens,including 7 SRC-RC transfer columns and 2 RC columns,all specimens are tested under low cyclic reversed loading.Hysteretic performance of SRC-RC transfer columns with shear cracking failure show serious pinch effect,rigidity dearades rapidly with increasing amount of cycles.More stirrups can improve the seismic resistance performance of SRC-RC transfer columns,the shear capacity and displacement ductility of SRC-RC transfer columns are better than those of RC columns.