带波形钢腹板挑梁的钢-混凝土组合脊骨梁设计计算方法

根据带波形钢腹板挑梁的钢-混凝土组合脊骨梁的小箱梁、大悬臂的结构特点,提出了考虑偏载效应影响的组合脊骨梁正应力计算公式;通过确定合理的抗弯极限状态,并基于简化塑性理论,推导出组合脊骨梁正、负弯矩截面的极限抗弯承载力计算公式和考虑混凝土翼板贡献的抗剪承载力计算公式;同时提出了波形钢腹板组合挑梁荷载横向分布计算的修正刚接梁法以及受载挑梁荷载横向分布系数随载位沿挑梁纵向变化而呈三次曲线分布的假设,并按照拟平截面假定,推导了波形钢腹板组合挑梁的开裂弯矩和弹性抗弯承载力计算公式。在此基础上进行了相应的模型试验研究,理论分析值和试验结果吻合良好,说明本文的设计公式精度满足要求,能够用于同类结构的设计计算。

Calculation Method for steel-concrete Composite Spine Girder Possessing cantilevered Beams with Corrugated steel Webs

According to the structural properties of the small box girder and large cantilever on the steel-concrete composite spine girder possessing long cantilevered beams with corrugated steel webs(SCCSG),the calculating formulas of normal stress considering the effect of eccentric loads were performed.Based on the simplified plastic theory,the calculating formulas on ultimate flexural resistance and shear strength considering contribution of concrete slabs in the positive and negative bending moment sections were derived by determination of the reasonable flexural limit state.Meanwhile,the modified rigid-jointed beam method for load lateral distribution of the composite bridge deck supported by paralleling long cantilevered beams with corrugated steel webs and the hypothesis that the load lateral distribution factor presents cubic curve along the longitudinal axis of composite cantilevered beam with the change of load acting point,were proposed.Then the calculating formulas on cracking moment and elastic bearing capacity of bending resistance of the composite cantilevered beams with corrugated steel webs were also investigated.On this basis,a series of tests were performed for a model beam.Comparison between theoretical solutions and model test results shows approximately satisfactory,which indicates that precision of the proposed calculating formulas can satisfy engineering requirement and can be used for design calculations of the same structure.