已下挠连续梁桥加固方案研究

针对目前一些大跨径预应力混凝土连续梁桥跨中长期挠度过大的问题，以汾江大桥为工程背景，分析导致该桥主梁挠度过大的主要原因。通过实测资料进行计算分析，说明体外预应力加固未能阻止主梁进一步下挠的原因。提出一种以钢箱梁替代跨中梁段的加固方案，通过计算分析其加固效果并与体外预应力加固进行对比，简单分析其可行性并展望应用前景。

Study on Reinforcement of Deflected Continuous Beam Bridge

At present, the long term deflection of some long span prestressed concrete continuous beam bridge is getting more and more serious. Aiming at this problem, taking Fenjiang Bridge as the engineering background, the reasons that lead to the deflection of the bridge are analyzed. Through calculations and analyses based on the measured data, it is explained why external prestressing did not stop the deflection of the bridge. A reinforcement method is proposed using steel box girder to take the place of the concrete box girder in the mid span, and the effect of this method is analyzed through calculating results. The feasibility of this method is discussed and its prospect is forecasted.