旧空心板简支梁桥的连续化改造加固研究

为提高既有旧空心板简支梁桥的承载能力和安全储备，将先简支后连续施工方法中的体系转换思想运用到旧空心板简支梁桥的加固改造上，提出了一种旧桥改造提载加固方案———简支连续化改造，并对此加固技术的实施方法进行了介绍；对简支连续化改造后的荷载效应以及连续化后新、旧混凝土收缩徐变效应进行了分析计算。结果表明：最不利工况下跨中最大弯矩下降了13．8％，边跨外侧支点最大剪力降低7．6％，中跨挠度最大减小42％；后浇墩顶连续段混凝土由新、旧混凝土龄期差引起的收缩徐变弯矩为正弯矩，对跨中截面受力不利，次边跨跨中弯矩最大增幅为3．9％；墩顶负弯矩有所下降，边跨墩顶负弯矩最大降幅为4．3％，影响均不显著。

Research on Continuous Transformation and Reinforcement for Old Simply Supported Hollow Slab Bridge

In order to improve bearing capacity and safety margin of the old simply supported hollow slab bridge in service ,the authors applied the system transformation thought that was used in the construction of transforming a simply supported bridge structure into a continuous one to the reinforcement of the old simply supported hollow slab bridge in service ,and put forward a method that could reinforce the old bridge and improve their bearing capacity of simply supported continuous transformation .Meanwhile ,the implementation method of this reinforced technology was introduced .The effect of load ,shrinkage and creep of the new and old concrete after simply supported continuous transformation was analyzed .The results indicate that the largest bending moment in the mid‐span is decreased by 13 .8% under the most unfavorable conditions ,and the maximum shear in the edge across the lateral pivot is reduced by 7 .6% ,and the deflection in the mid‐span is even decreased by 42% .T he bending moment led by the shrinkage and creep of the new and old concrete with different ages on pier top is positive bending moment ,which is harmful to the force in cross section .T he bending moment in the cross section of the secondary side span across is the biggest increase by 3 .9% .Negative bending moment value on pier top decreased at the same time ,the biggest decrease of that in the side span is 4 .3% ,so the effects are not signifi‐cant .