偏心夹心梁柱节点低周反复加载受力性能试验研究

EXPERIMENTAL STUDY ON BEHAVIOR OF ECCENTRIC BEAM-COLUMN SANDWICH JOINTS UNDER CYCLIC LOADING

实际工程中梁和柱的混凝土强度经常不同,节点部位按照梁的混凝土来浇筑是这种情况下施工处理最为简便的方式,形成所谓的"夹心"节点。一些研究者就夹心节点在单调加载和低周反复加载下的性能进行了研究,但对夹心节点同时又存在梁柱偏心的情况还没有研究先例。该文完成了3个偏心夹心梁柱节点的低周反复加载试验,并分析了其节点区抗剪承载力、破坏特征、滞洄耗能等性能。结果表明:此类偏心夹心节点具有良好的承载能力和抗震性能,并且在节点区布置X筋替代部分箍筋是可行的,但梁筋在节点区的锚固性能较弱,需采取控制措施。

In engineering practice,the columns and beams are often designed with different concrete strength.In such cases,it is convenient to cast the joints with the same concrete as those of beams instead of those of columns.Consequently,the so called sandwich joints are resulted in.A few researchers have carried out by means of both static and cyclic loading experiments of such sandwich joints.However,there have not been tests for sandwich joint with eccentricity of a beam and a column.Three specimens of eccentric sandwich joints in middle floor of a frame were designed and loaded under cyclic loading.Their shear capacity,failure modes,and ductility,as well as energy dissipation were analyzed.The results show that the performance of eccentric sandwich joints is good under cyclic loading.X-type reinforcements can be used to partially substitute for stirrups in the joint to bear shear forces.The anchorage of longitudinal bars of beams in eccentric sandwich joints is relatively weak.