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.
The PBL shear connector used to connect the corrugated steel ribs and concrete roof of long- span continuous rigid frame bridges has its unique structure,mechanics,and stress environment characteristics. In order to study the load-slip properties and bearing capacities of this kind of PBLshear connectors, failure tests were carried out with static loads using 33 specimens in 13 types of 3- hole models （3 specimens for each model type） , in which transverse tensile and compressive prestresses were applied to the specimens with jack and finishing rolling rebar. Through the tests, the concept and value of a design bearing capacity were proposed and fitting formulas of the design bearing capacity and the ultimate bearing capacity were obtained. The results show that when the load is smaller than the design bearing capacity, the PBL connector works in the elastic stage with a slip less than the specified limit. The load-slip curves obtained from tests can be segmented into elastic stage, elastoplastic stage,yielding stage, and partially reinforcing stage. Under a concentrated loading condition, the bearing capacity calculated by average of the load bom by the 3 holes is obviously smaller than the actual value. In addition, the transverse tensile prestress reduces the design bearing capacity and ultimate bearing capacity of the PBL shear connectors by about 0. 020 and 0. 043 kN, respectively, while the transverse compressive prestress benefits the bearing capacity of the shear connectors. The effect of prestress on bearing capacity can be considered separately.
出处
《西南交通大学学报》
EI
CSCD
北大核心
2017年第4期647-654,共8页
Journal of Southwest Jiaotong University
关键词
PBL剪力键
预应力
设计承载能力
极限承载能力
PBL shear connectors
prestressed force
design bearing capacity
ultimate bearing capacity
