节段预制拼装梁胶接缝抗剪承载力参数分析

Parameter Analysis of Shear Bearing Capacity of Adhesive Joint of Segmental Precast Assembled Beam

为合理设计节段预制拼装梁剪力键齿胶接缝的抗剪承载力模型试验,采用ABAQUS软件建立试验模型,混凝土本构关系采用考虑塑性损伤的非线性本构模型,接缝间环氧树脂胶采用弹性材料模拟。建立两个块件胶结组合的单面剪切试验模型,并与三个块件胶结组合的双面剪切试验模型对比,发现单面剪切试验模型加载不对称,抗剪承载力计算值偏大,因此采用双面剪切模型对剪力键齿竖向埋入深度、端部块件宽度、中间块件宽度、正应力、混凝土强度等级、胶层厚度进行参数分析。结果表明:剪力键齿在竖向埋入深度不宜过小,设计值宜与齿根竖向高度一致;端部块件宽度不必过大,中间块件宽度不能过小,均取键齿水平方向尺寸的9倍;正应力水平和混凝土强度等级对抗剪承载力影响较大,应在试验模型中精确控制;环氧树脂胶层厚度在0.5~4.0 mm时,胶层厚度对抗剪承载力影响小,对胶层施工精度的要求可以适当降低。

In order to reasonably design the shear bearing capacity model test of the shear key tooth adhesive joints of segmental prefabricated beams,the test model was established by ABAQUS software. The nonlinear constitutive considering the plastic damage was adopted for the concrete constitutive relationship,and the epoxy resin adhesive between joints was simulated by elastic material. The single-side shear test model of two blocks cemented combination was established and compared with the double-side shear test model of three blocks cemented combination. It is found that the loading of the single-side shear test model is asymmetric and the calculated value of shear bearing capacity is too large. Therefore,the double-side shear model is used to make parametric analysis on the vertical embedding depth of shear key tooth,the width of end block,the width of middle block,normal stress,concrete strength grade and adhesive layer thickness. The results show that the vertical embedding depth of the shear key tooth should not be too small,and the design value can be highly consistent with the vertical height of the tooth root. The width of the end part should not be too large,the width of the middle part should not be too small,both of them can be adopted as 9 times as the size of the horizontal dimension of the key tooth. The normal stress and concrete strength grade have a great influence on the shear bearing capacity and should be precisely controlled in the test model. When the thickness of epoxy resin adhesive layer is 0.5 ~ 4.0 mm,the thickness of adhesive layer has little effect on the shear bearing capacity,and the requirements for the construction accuracy of adhesive layer thickness can be appropriately reduced.