大跨度混凝土连续梁桥的病害成因分析

自20世纪80年代以来,我国建成了大量大跨度预应力混凝土连续体系桥梁,取得了辉煌成就,但随着桥梁建设数量与使用年限的增加,该类桥梁在施工与运营期陆续出现一些具有共性的病害:跨中挠度过大、箱梁开裂与跨中合龙段底板剥离等,而且有些病害已经导致桥梁重大的安全事故与经济损失。文章对国内数十座桥梁出现的病害随时间变化发展的趋势、在空间上分布的形态等进行了分析。根据现有的理论研究成果,分析了腹板斜裂缝、底板纵向裂缝、合龙段底板分层等病害的形成机理,提出了控制裂缝等病害发生的措施,并说明了这些控制措施在泰州大桥预应力桥梁上的应用情况。

Mechanism and control of existing faults on long span concrete continuous system bridges in China

Since 1980's, a lot of long-span prestressed concrete continuous system bridges have been constructed in China, and great success has been achieved. However, with the increase of numbers and service life of bridges, some similar diseases have been showed in this kind of bridges in succession. In this paper, the forms of many typical faults like excessive deflection in the mid-span, box beam crack and bottom slab stripping in the closure segment of mid-span, etc. , have been summarized. And the characteristics of these faults'happening time, trend of development and distribution form have been pointed out. Their causes and corresponding prevention countermeasures have been analyzed. At last the direction which needs further study about the theory of computa-tion and the measures which should be taken in design have been figured out