钢混凝土组合桥面板负弯矩区裂缝宽度计算

Crack Width Calculation of SteelConcrete Composite Bridge Deck in Negative Moment Region DAI Changyuan, SU Qingtian

摘要:

制作了5个组合桥面板试件并进行负弯矩加载试验，结果发现组合桥面板在混凝土开裂后截面内钢筋、钢板的应变不符合平截面假定，钢筋应变明显大于按照平截面假定求得的计算值.理论推导了组合桥面板混凝土开裂后截面钢筋应力的计算公式，并与试验结果对比，计算值与实测值吻合较好.对不同的混凝土裂缝宽度计算方法进行对比发现：采用本文推荐的钢筋应力公式，并使用公预规提出的混凝土裂缝宽度计算公式按照偏心受拉构件计算，得到的结果与实测值吻合较好.

关键词:组合桥面板; 混凝土开裂; 裂缝宽度; 钢筋应力

Abstract:

Five steel concrete composite bridge deck specimens were manufactured and subjected to negative moment loading. It could be observed that the strain of rebar and steel plate of splitting section does not obey the plainsection assumption. The strain of rebar is obviously larger than the value calculated according to the plainsection assumption. Then, a formula which can be used to calculate the rebar stress of cracked section was deduced. The calculating results agreed well with the test values. Finally, different crack width predicting methods were compared. The results show that when using the formula recommended in this paper to calculate the rebar stress, adopting the crack width calculation formula specified in JTG D62 2004 and using the parameters of eccentric tension member, the calculated crack width agrees well with the test values.

Key words:composite bridge deck; concrete crack; crack width; rebar stress