Investigation on the Application of External Prestressing Technology in Bridge

Abstract

To systematically evaluate the long-term performance of external prestressing technology and promote its engineering application, the international journal Prestress Technology of Tongji University recently organized a specialized symposium and conducted onsite follow-up visits and technical exchanges on two representative projects—the Xintan Qijiang Highway Bridge in Chongqing (completed in 2008) and the Qingquan Temple Jialing River Bridge in Nanchong, Sichuan (strengthened in 2014). The investigation revealed that, as China’s first long-span continuous rigid-frame bridge employing a hybrid internal-external prestressing tendon system, the Xintan Qijiang Bridge has maintained good technical conditions in its right span with a hybrid tendon layout after 17 years of service, with no structural load-induced cracks, which fully verifies the long-term reliability and durability of the external prestressing system. Moreover, ten years after the implementation of comprehensive strengthening measures—including internal-box external prestressing—the Qingquan Temple Jialing River Bridge also remained structurally stable. On the basis of these findings, experts have recommended the development of dedicated inspection guidelines for external prestressing systems, with a focus on critical components such as anchorages and deviators, and the promotion of nondestructive testing and intelligent monitoring technologies. This investigation not only provides valuable empirical support for the application of external prestressing technology in both new and reinforced bridges but also emphasizes the importance of integrated collaboration among research, industry, management, and maintenance for the sustainable advancement of the technology.

Keywords

external prestressing / hybrid internal-external prestressing system / bridge strengthening

References

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