大跨径连续梁桥拼宽方案比选研究

Study on Scheme Comparison of Long Span Continuous Beam Bridge Widening

大跨径桥梁的扩建作为改扩建项目的控制性工程,成为了改扩建项目需要重点解决的难题。本文依托于长春至深圳国家高速公路河源热水至惠州平南段改扩建项目东江大桥,针对大跨径连续梁桥不同的改扩建方案进行了深入比较,分别对两侧拼宽和左侧拼宽方案进行了建模分析,计算发现,两侧拼宽新旧桥梁刚性拼接后,受基础不均衡沉降、收缩徐变等因素影响,拼宽后桥梁受力状态复杂,旧桥承载力不足,拼宽侧新桥出现拉应力,不利于桥梁的全生命周期的运营,左侧拼宽分离新建桥梁,桥梁受力明确,新旧桥梁独立运营,也可为后期的旧桥拆除重建预留条件,综合比选后,最终确定了合理可行的方案。

Long span continuous beam bridge widening as a controlling project of the expansion project,has become a key problem.Relies on the Dongjiang Bridge of the reconstruction and expansion project of the Changchun-Shenzhen National Expressway from Heyuan Reshui to Huizhou Pingnan,and conducts an comparison of different expansion plans for large-span continuous girder bridges.The widening scheme was modeled and analyzed,and calculations found that after the rigid splicing of the new and old bridges by widening on both sides,it is affected by factors such as unbalanced foundation settlement,shrinkage and creep.After widening,the stress state of the bridge is complex and the old bridge’s bearing capacity is insufficient.Tensile stress appears on the new bridge,which is not conducive to the operation of the full life cycle of the bridge.The left side is widened to separate the newly built bridge,the bridge is clearly stressed,and the old and new bridges are operated independently.Conditions can also be reserved for the later demolition and reconstruction of the old bridge.After the comparison,a reasonable and feasible plan was finally determined.