多跨空心板简支梁桥整体化改造设计

以某多跨空心板简支梁桥工程为例，在病害调查、技术状况评价的基础上，提出了取消全桥伸缩缝和支座的全桥整体化改造方案，包括拆除桥梁上部结构，新设计的上部结构体系仍采用预制空心板，结构体系为先简支后连续结构；对桥台处主梁和连接结构进行改造，取消桥墩和桥台处的伸缩缝，同时取消全桥支座，将上、下部结构通过钢棒连接。最后对该桥整体化改造前后的受力性能进行对比分析。结果表明:这种通过体系转化的主动加固方法可以提高结构的承载力，改善结构的受力状况；将该桥改造成为整体式桥梁可以有效提高其使用性能，免除伸缩装置和支座的养护、维修，提高桥梁的可持续发展能力。

Integral Transformation Design of Multi-span Hollow Slab Simply-supported Bridge

Taking a multi-span hollow slab simply-supported bridge as example, a new kind of integral transformation scheme by canceling the whole bridge expansion joints and bearings was proposed based on the disease investigation, technical condition evaluation. The integral transformation design of the bridge included removing the superstructure of the bridge, and the new superstructure system still used precast hollow slab, whose structural system was from the simply-supported structure to the continuous one. Then the connection structure between the beam end and the approach slab was transformed by canceling the expansion joint of the bridge pier and abutment. The superstructure and substructure were connected by the steel bar after canceling the whole bridge bearing. Finally, comparison and analysis of the mechanical behaviors before and after integral transformation of the bridge were carried out. The results show that the kind of active reinforcement method by the system transformation can improve the bearing capacity and the mechanical performance of the structure. The transformation of integral bridge can effectively improve the usability, avoid the maintenance and repairing of bridge expansion joints and bearings, and improve the ability of sustainable development of the bridge.