斜拉桥锚固区栓钉剪力键力学特性研究

Experimental Research on Stress Behavior of Stud Shear Connector in Tower Anchorage Area of Cable-stayed Bridge

针对栓钉剪力键用于斜拉桥索塔锚固区连接部位时的应力应变特性,以中部横梁均匀加载为思路,建立局部试验模型,以栓钉剪力键的极限承载力为依据,设计加载方案,通过试验获取栓钉的应变随荷载变化的基本特征,并分析了破坏机理。结果表明:中部加载使模型两侧剪力键受力均匀,设计更为合理;栓钉剪力键的剪应力以加载梁为中心向两侧逐渐降低;高度方向,第7排栓钉受力最大,长度方向,单钉根部受到的剪力最大,应作为控制截面;破坏时,栓钉弯曲变形,根部发生45°剪切破坏,混凝土局部产生裂缝或压碎破坏。

This article mainly studied the stud shear connector for anchorage zone of pylon cablestayed bridge connecting parts when subject to stress-strain characteristics. Taking central uniform load for ideas established local test model. Loading program was designed which based on the ultimate bearing capacity of stud shear connector. It has acquired the basic characteristics of stud strain with load variation and analyzed the failure mechanism. The results showed that： The model adopts central loaded design is more reasonable because it makes shear connector force uniform on both sides of the model. The shear stress of stud shear connector decreased gradually from the center to both ends of the load beam. In the height direction,the 7th rows of pegs subject the maximum shear stress. In the longitudinal direction,single nail roots subject the maximum shear stress. It should be used as the control section. When the stud destruction,the stud bending deformation occurs,peg roots shear failure in direction of 45°,the partial concrete will produce cracks or be crushed.