预制拼装混凝土节段梁弯剪性能研究

Research on Flexural Shear Performance of Prefabricated Concrete Segmental Beams

摘要:

为明确预制拼装节段梁的弯剪性能和传力机理，通过建立相应的非线性有限元模型并结合实验数据进行验证，分析了不同构造参数对节段梁剪力键接缝弯剪性能的影响。研究表明：剪力键的布置位置和剪力键键块深度对节段梁抵抗弯剪荷载的性能具有显著影响；键齿位于梁截面中部的剪力键能更有效地传递剪力，提高整体承载能力；布置在较长节段上的剪力键承载能力和延性均优于布置在短节段上；剪力键键块深度增加可提高结构抗弯剪性能，但提升效果在剪力键键块深度为键高0.4倍时趋于饱和，过深反而可能增加加工难度和局部压碎风险。建议在设计中取剪力键键块深度为键高的0.4倍，以兼顾节段梁的承载性能和施工可行性。

Abstract:

To elucidate the flexural shear performance and load-transfer mechanism of prefabricated segmental beams, by establishing nonlinear finite-element models and verifying them with the experimental data, the influence of different construction parameters on the flexural shear performance of shear key joints in segmented beams is analyzed. The results indicate that the layout position of shear key and the block depth of shear key have a significant impact on the performance of segmented beams in resisting flexural shear loads. The shear keys with key teeth located in the middle of the beam section can more effectively transfer shear force and enhance the overall load-bearing capacity. The load-bearing capacity and ductility of shear keys arranged in longer segments are both superior to those arranged in shorter segments. Increasing the depth of shear key block can improve flexural shear performance of structure, but the enhancement effect tends to saturate when the depth of the shear bond block is 0.4 times the key height. The excessive depth may increase the processing difficulty and the local crushing risk. It is recommended that in the design, the depth of the shear key block be 0.4 times the key height to take into account both the load-bearing performance and the construction feasibility of the segmented beam.