中小跨径公路桥行车道的改建,可采用在主梁上面敷设带悬臂的整体式、装配式或装配整体式桥面板的办法加宽。但是,这种结构由于后敷没的桥面板的自重作用,使主梁的负荷增加,可能要求加固原有主梁。此外,由于板的厚度小,悬臂加宽有限,悬臂部分只能布置人行道,行车道的 Small and medium-span highway bridge roadway reconstruction, can be used in the main beam above the laying of a cantilevered monolithic, assembly or installation of integrated bridge deck widens. However, due to the self-weight of the bridge deck which is not covered by this structure, the load of the main beam is increased, which may require the reinforcement of the existing main beam. In addition, due to the small thickness of the plate, cantilever widening is limited, the cantilever part can only be arranged sidewalks, lane