装配组合钢箱梁桥负弯矩区结合部受力性能研究

Mechanical behavior on negative moment joint section of prefabricated composite box girder bridge

为降低装配式组合钢箱梁桥结构体系转换时中支座处结合部的施工难度,提出一种钢-混凝土结合部的构造形式。应用有限元分析软件ANSYS,通过对某4跨连续梁桥的模拟计算,揭示了结合部各构件传力比例及钢-混凝土界面滑移机理。进一步变化连接件布置形式及抗剪刚度,研究不同参数对结合部受力性能的影响。结果表明,结合部通过桥面板及内插开孔钢板的纵向力传递支点负弯矩,隔板焊钉及内填充混凝土传递竖向支反力;随着连接件布置方式及抗剪刚度的变化,不同参数对隔板焊钉受力影响较大,对其余构件基本无影响;结合部混凝土绝大部分主拉应力低于2.1 MPa,焊钉最大剪力为12.6 k N,钢-混凝土结合面最大滑移为0.06 mm,结合部构造形式安全、合理。

In order to reduce the construction difficulties of the joint section on middle bearings,a new kind of steelconcrete joint section is proposed. Based on one four-span bridge,a finite element model which considered the slip effect between steel plates and concrete was established using ANSYS to simulate force transfer mechanism. Parametric analysis was conducted and the design of setting shear connectors was optimized. The results show that counting on the longitudinal force,perfobond connectors and decks transfer bending moments from one span to another. The vertical shear forces are transferred by shear studs and filled concrete. When changing arrangement and shear stiffness of shear connectors,only vertical forces of shear studs are influenced. The principle tensile stresses of concrete in most area are under 2. 1 MPa,the maximum shear force of shear studs is 12. 6 k N and the biggest slip between steel plates and concrete is 0. 06 mm. This kind of steel-concrete joint section is safe and reasonable.