低周反复荷载下型钢混凝土柱-钢筋混凝土梁异形节点破坏机理及受力性能研究

型钢混凝土框架-混凝土分散剪力墙火电厂主厂房结构体系中存在着大量钢骨混凝土柱-钢筋混凝土梁异形节点,该类节点属于变柱、左右梁高不等且存在错层的异形节点,通过低周反复加载试验研究该类节点的破坏机理和受力性能。研究结果表明:该类节点破坏过程均经历了初裂、通裂、极限、破坏4个特征阶段,最终均发生柱端塑性铰破坏。在强震作用下,型钢混凝土结构相对于普通钢筋混凝土结构构件具有良好的后期变形和承载能力。该类异形节点的受力机理可以通过斜压杆模型与钢桁架模型解释。

STUDY OF FAILURE MECHANISM AND MECHANICAL BEHAVIOR OF ABNORMAL JOINTS BETWEEN STEEL REINFORCED CONCRETE COLUMN AND REINFORCED CONCRETE BEAM UNDER LOW-CYCLE REVERSED LOADING

In the main power house structures of the thermal power plant with SRC frame-RC scattered shear wall,there are plenty of abnormal joints between steel reinforced concrete column and reinforced concrete beam. These joints belong to the type of abnormal joints with cross-section mutation column,beams on either side of the column being not on the same level and staggered floor,and low-cycle reversed loading experiments were carried out for the abnormal joints to research their failure mechanism and mechanical behavior. The results indicate that the failure process of the joints experienced four stages of initial crack,entire crack,limited crack and failure. Finally,these joints were failed by the destruction of column end plastic hinge. Steel reinforced concrete structure members have better late deformation and bearing capacity than ordinary reinforced concrete structural members under strong earthquake. The stress mechanism of these abnormal joints could be explained by compression strut mode and steel truss mode.