Status and Development of Maintenance and Strengthening Technologies for Existing Prestressed Concrete Cable-Stayed Bridges

More and more engineers have been attracted by the maintenance and strengthening aspects of pre-stressed concrete cable-stayed bridges. For an existing pre-stressed concrete cable-stayed bridge, replacement of stay cables plays a key technique in prolonging service life and also adjustments of stay cable forces has become a critical technique in the improvement of structural behaviors. External bonding and enlarging cross-sections are often adopted in the maintaining and strengthening procedures for pre-stressed concrete cable-stayed bridges. In the past decade, China witnessed a rapid development in the maintenance and strengthening of pre-stressed concrete cable-stayed bridges. Especially in the recent the Tianjin Yonghe Bridge; both the replacement of closure segments in the middle and tension rocker bearing cables at the subsidiary piers have provided opportunities for new trials and explorations. These creative methods have offered novel alternatives to maintain and strengthen pre-stressed concrete cable-stayed bridges. Furthermore, the Integrated Maintenance and Strengthening Technique will also become a future trend.