Abstract: The 55-km-long Hong Kong-Zhuhai-Macao Bridge (HZMB) is the world's longest sea-crossing bridge, connecting Hong Kong with Zhuhai and Macao at the mouth of the Pearl River Estuary in China. Due to the construction constraints such as high temperature, high humidity, high salt and windy offshore environment, dense sea routes,low obstruction rate of the water flow,life cycle cost,durability, and so on,the steel structure bridge, as the preferable bridge type, is the most reasonable choice for HZMB. The total length of the steel structure bridge of HZMB is about 22.9 km and the steel consumption is 425 000 t, and it is the largest scale and the longest designed service life at home and abroad, therefore, the manufacturing of the steel structure of this bridge is full of challenges.
To meet this challenge, at the beginning of the project, the HZMB management team conducted an in-depth investigation of the steel structure manufacturing industry at home and abroad, focusing on the gaps in computer-aided design, automatic manufacturing, detection technology, and construction management between domestic and foreign, and seeking for improvement methods. At that time, the steel structure manufacturing and processing level of China could not complete the manufacturing of 425 000 t of steel structures with high quality and efficiency within 48 months. To this end, the management team carried out the transformation and upgrading of the manufacturing model and the innovative planning of the management model, including the automation and intellectualization of steel plate element manufacturing, industrialization of assembly and painting workshop, full coverage of detection, flattening and internationalization of management, and manufacturing informatization management, etc. The construction and operation of the comprehensive innovation system for the steel structure manufacturing of the HZMB was successfully realized, the steel structure manufacturing of HZMB was completed with high quality and rich technical achievements, which mainly include:the automatic and intelligent production line for plate element, the factory assembly and mechanized coating of in large segments, the PAUT technical standard for the U-rib weld and the group welding information management system, the large-segment offshore installation and control technology, the accessible, detectable and maintainable design, and management innovation, etc.
At the end of the article, some thoughts and suggestions on the development of China's steel structure bridge industry were put forward based on the practical experience of the HZMB. Through the planning and practice of the steel structure manufacturing of the HZMB, it can be seen that:1)The requirement of standardization, factorization, and large-scale segment promotes the technological innovations in each construction stage of HZMB. The application of mechanization, automation, and information technologies has improved the overall construction and management level. 2)The extensive offshore assembly constructions promote the development, application of large offshore equipment, and innovative hoisting methods. 3)Standardization of technology and management enables the effective implementation of the concept of full process control. 4)In accordance with the concept of equal emphasis on construction and maintenance, the development of accessible, detectable and maintainable design can promote the lowest life-cycle cost of steel structure bridges. The construction of the HZMB has promoted the progress of China's steel structure industry and provided rich and valuable experience for the development of the industry. The 55-km-long Hong Kong-Zhuhai-Macao Bridge (HZMB) is the world's longest sea-crossing bridge, connecting Hong Kong with Zhuhai and Macao at the mouth of the Pearl River Estuary in China, comprising 22.9-km-long steel bridges. HZMB is the leading steel bridge in China, with top-level manufacturing and installation technology. This paper outlines the steel bridge construction experiences of HZMB to provide comparisons for the construction of other long sea-crossing steel bridges at home or abroad. The main considerations of construction background, constraints, manufacturing market survey, procure strategies, scheme selection, structural and aesthetic design of HZMB are presented, and the following points related to new strategies in the steel bridge preliminary and construction stage of HZMB are elaborated:(1) biding strategy, (2) automatic manufacturing technology, (3) large segment offshore installation, (4) eco-friendly paint (content limitation of volatile organic compounds). The successful implementation of those strategies shows that the steel bridge construction of HZMB promotes improvement in the overall construction and management level of the Chinese bridge industry.