单箱双室波形钢腹板-钢底板组合梁滑移效应研究

Study on Slip Effect of Two-Cell Box Girder with Corrugated Steel Webs and Steel Bottom Plates

为了解剪切变形、剪力滞效应及滑移效应对单箱双室波形钢腹板-钢底板组合梁力学性能的影响,基于能量变分原理,推导该类组合梁的总挠度、界面滑移量及正应力解析解。以某等截面简支单箱双室波形钢腹板-正交异性钢底板组合梁为背景,通过理论分析、模型试验和有限元计算相结合的方法,分析考虑滑移效应的组合梁关键截面总挠度、界面滑移量及混凝土顶板横向正应力。结果表明:在集中荷载作用下,组合梁的总挠度、界面滑移量和横向正应力的解析解与实测值及有限元解吻合良好;由于附加弯矩的存在,剪切变形及界面滑移效应对组合梁总挠度的影响均不能忽略;组合梁的总挠度和界面滑移量随剪力钉抗剪刚度的增大不断减小,但减小的趋势逐渐放缓。施工设计时,可将剪力钉的抗剪刚度控制在挠度变化趋于平缓的范围内。

In this paper,the influences of shear deformation,shear lag effect and slip effect on the mechanical properties of the two-cell box girder with corrugated steel webs and steel bottom plates are investigated.Following the energy-variational principle,analytical solutions of the total deflection and interface slippage as well as normal stresses of this type of composite girder are derived.An existing constant-cross-section,simply-supported two-cell box girder with corrugated steel webs and orthotropic steel bottom plates is used for a case study.Theoretical analysis is accompanied with model test and numerical simulation to analyze the total deflection and interface slippage as well as transverse normal stresses in concrete top slabs of the key cross-sections,considering the slippage effect.It is shown that analytical solutions of the total deflection and interface slippage as well as transverse normal stresses of the composite girder agree well with the test results and numerical calculations.Due to the existence of additional bending moment,the influences of shear deformation and interface slippage effect on the total deflection of the composite girder should not be ignored.As the shear stiffness of shear studs increases,the total deflection and interface slippage of the composite girder keep decreasing,but the decreasing becomes weaker and weaker.In the construction design,the shear stiffness of shear studs can be controlled within the flattened variation range of the deflection.