钢箱-砼组合结构带孔加劲肋套箍剪力键群抗剪试验研究

摘要

在PBL剪力键的基础上,提出了适用于钢箱-砼组合结构的带孔加劲肋套箍(PBH)剪力键(perfobond hoop,PBH).在PBH现有单排及多排研究基础上,为更加贴近在结构中的真实受力方式,进一步增加共同受力的剪力键数量,对PBH剪力键群进行了以沿抗剪方向剪力键排数为参数的推出试验,其中排数为3、5、7、9、11共5类试件.试验得到PBH剪力键群的荷载-滑移全过程曲线、承载力、破坏形态及滑移分布规律.其破坏形态为混凝土劈裂破坏及穿孔钢筋受弯屈服;沿高度方向的界面滑移呈现"两端大中间小"的分布规律;PBH群抗剪极限承载力随剪力键排数增加而折减,且排数越多,折减越多.折减效应分析认为,该折减的原因来自于沿抗剪界面的滑移分布不均匀.并由此提出了PBH群承载力折减系数.%The PBH shear connector which is suitable for steel-concrete composite structure (perfobond hoop, which is abbreviated as PBH in the following sections) is put out on the basis of PBL shear connectors.In order to make the real force mode closer to the structure, the subsequent study by increasing the number of the shear key is carried out after the existing single row and multi-row research on PBH.The push-out test of PBH shear connectors group is designed to test the parameters of the number of shear connectors row along the shear direction, which ranked 3, 5, 7, 9, 11, and there is a total of 5 specimens in all.The load slip of whole process curve, bearing capacity, failure mode and slip distribution of PBH shear connectors group are obtained.There are two main failure modes which are concrete splitting failure and perforated steel flexural.The distribution of the interface slip along the height presents the rule of "large at two poles and small in the middle".The ultimate shear capacity of PBH reduces with the increases of the row number, and the more row, the more reduction.According to the analysis of the capacity reduction rule, the reduction comes from the uneven distribution of the slip along the shear interface, and the load reduction factor of PBH group is proposed.