Novel design and accelerated construction for long-span extradosed cable-stayed bridges

Over the past two decades, the construction of long-span extradosed cable-stayed bridges (CSBs) has experienced rapid growth, with numerous innovative designs and construction methods emerging in recent years. This study presents a comprehensive synthesis of innovative designs and accelerated construction methods for long-span extradosed CSBs. A database of 162 bridges worldwide, including 118 in China, was compiled and analysed in terms of nine key design parameters. Innovative designs for extradosed CSBs addressing extended-span configurations, wide-deck geometries and mountainous regions are presented. These encompass hybrid girder systems and multi-tower configurations suitable for extended spans, corrugated steel–concrete hybrid web structures for wide-deck applications, as well as horizontally curved alignments and ultra-tall pier configurations suitable for challenging mountainous conditions. The effectiveness of two representative accelerated construction methods, namely swivel construction and integral jack-up construction, is verified through reported engineering practice. The former is assessed mainly by swivel tonnage and angular velocity, whereas the latter is evaluated by lifting tonnage, lifting speed, girder stress increment and stay-cable force variation. This paper reveals differences in key design parameters between Chinese and international long-span extradosed CSBs and summarises key control factors for swivel and integral jack-up construction, thereby providing guidance for design and construction.