Abstract:Taking a small urban bridge in the urban area of Shanghai that has been in service for nearly 40 years as an example, in view of typical diseases such as cracks in the bridge structure and rusting of the main beam concrete, as well as the current situation of a nearly 25% decline in bearing capacity, based on multiple rounds of inspection data from 2012 to 2024, the evolution law of diseases was systematically analyzed. Adhering to the concept of low-impact renewal, under the premise of maintaining the original design load and bridge deck profile, a maintenance plan of "rebuilding the bridge deck system + overall replacement of the superstructure + local reinforcement of the substructure" was proposed, and a construction organization mode of phased and sectional construction was adopted to minimize the disturbance to regional traffic operation and the surrounding environment during construction. From three aspects of disease diagnosis, renewal strategy, and construction organization, the technical path of low-impact renewal for small urban bridges was summarized, which can provide a reference for similar projects.
