预应力PBL剪力键的承载能力试验研究

发布时间：2018-07-28 21:43

【摘要】：大跨度波形钢腹板箱梁桥中波形钢腹板与顶板混凝土之间PBL剪力键有其独有的构造、受力及应力环境特点,为了研究这类剪力键的荷载-滑移曲线特征和承载能力,对13组三孔模型共33个试件进行了静载破坏试验,分别通过千斤顶和精扎螺纹钢筋对试件施加横向预拉和压应力,提出了设计承载能力的概念、取值方法、设计承载能力和极限承载能力的拟合计算公式.研究结果表明:当荷载小于设计承载能力时,剪力键处于弹性工作阶段,且滑移量不超过规定的限值;荷载-滑移曲线可分为弹性阶段、弹塑性阶段和屈服阶段,部分存在强化阶段;以集中荷载方式加载时,按3个孔所承担荷载平均值得出的承载能力明显偏小;横向预拉应力对设计承载能力和极限承载能力的降低值分别为0.020、0.043 k N,横向预压应力使剪力键的承载能力提高并起有利作用,预应力对承载能力的影响可单独考虑.
[Abstract]:The PBL shear bond between the corrugated steel web and the roof concrete in a long-span corrugated steel box girder bridge has its unique structure, stress and stress environment. In order to study the load-slip curve and load-carrying capacity of this kind of shear bond, A total of 33 specimens of 13 groups of three-hole models were subjected to static load failure tests. The concept of design load-bearing capacity and the method of selecting values were put forward by applying transverse pretension and compressive stress to the specimens through Jack and fine thread reinforcement respectively. Design the fitting formula of bearing capacity and ultimate bearing capacity. The results show that when the load is less than the designed bearing capacity, the shear bond is in the elastic working stage, and the slip value does not exceed the specified limit, and the load-slip curve can be divided into three stages: elastic stage, elastic-plastic stage and yield stage. The loading capacity of the three holes is obviously smaller when the load is loaded in a concentrated load mode, and the average value of the load carried by the three holes is obviously smaller than that of the average load carried by the three holes. The decrease of transverse pretension stress to the design load capacity and the ultimate bearing capacity is 0.020 ~ 0.043 KN, respectively. The transverse preloading stress increases the bearing capacity of the shear bond and plays a beneficial role. The influence of prestress on the bearing capacity can be considered separately.
【作者单位】：中铁二院工程集团有限责任公司;西南交通大学土木工程学院;
【分类号】：U446.1

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