后锚固设计中的锚板刚度研究

Research on the stiffness of anchor plate in post-installed anchor design

对钢柱脚连接"底板设计"和后锚固安装"锚板设计"的概念及两者区别分别按破坏模式、受力机理和设计方法做了阐述。现行规范的后锚固设计是基于刚性锚板的假定,而实际工况的锚板变形将会对锚栓和混凝土基材的破坏模式和受力机理有影响。基于新研发带组合构件方法的有限元锚栓设计软件,对比了后锚固安装锚栓在刚性锚板和柔性锚板下承受拉力、剪力和弯矩荷载的应力分布。结果表明:与刚性锚板相比,柔性锚板在受拉工况下会出现锚固点的混凝土基材剪撬破坏;在受压工况下混凝土基材会发生局部挤压破坏;在弯矩工况下会导致内力臂的减少,相应地增加了锚栓的受力荷载。结合实际工程经验,给出了柔性锚板设计的判断方法和建议。

The concept of anchor plate design for steel column and anchor design for post-installed fixing and their differences were described respectively according to failure mode,force mechanism and design method.The design of post-installed anchor in current codes is based on the assumption of rigid anchor plate.However,the deformation of anchor plate in real situation will have influence on failure mode and force mechanism of anchor and concrete base material.Based on the newly developed finite element anchor design software with composite component,the stress distribution of rigid and flexible anchor plate for post-installed anchor under tension,shear and moment force was compared.The results show that compared with the rigid anchor plate,the prying failure of concrete base material at the fixing point will occur for the flexible anchor plate under tension force;the local crush or damage will occur in the concrete base material under compression force;the inner arm will be reduced under bending moment and the force applied to anchor will be increased accordingly.Combined with practical engineering experience,the judgement methods and suggestions for the design of flexible anchor plate are given.