Pavement structure and materials design for sea-crossing bridges and tunnel: Case study of the Hong Kong–Zhuhai–Macau Bridge

With the continuous development of bridge and tunnel construction technologies, large-scale sea-crossing bridges and tunnels have gradually become the preferred choice for regional traffic. The construction technology of Hong Kong-Zhuhai-Macau Bridge (HZMB), one of the most representative sea-crossing passageways, is instructive for the construction of other large sea-crossing infrastructures. At present, the pavement design method of sea-crossing passageways lacks pertinence as it still refers to specifications for design of common pavement. Therefore, it is necessary to consider the bridge and tunnel pavement of HZMB as a typical example to analyze key technical problems encountered in its design, construction and operation. Novel solutions for material selection and structural design built upon the analysis of such critical problems should thus follow up. Based on comprehensive literature research, it can be found that environmental variability, tunnel closure, structural differential settlement and expansion deformation are the key technical problems faced by pavement of sea-crossing passageways. In view of the environmental variability, the steel deck-paving material and structure design of GMA-10 + SMA-13 is innovatively proposed. As for the closure of immersed tube tunnel, warm-mix flame retardant asphalt mixture is used to control pavement design through key indexes such as temperature and limit oxygen index. Regarding the deformation of immersed pipe joints, BJ200 asphalt seamless expansion joint material is introduced, which effectively satisfies the multi-directional deformation between pipe joints and ensures the smoothness of the road surface and driving comfort. For segmental joints, double-layer waterproof-coiled material is used to effectively prevent reflective cracks while ensuring the continuity of asphalt concrete pavement. Therefore, this paper provides a panel of ideas and methods for the pavement design of the same type of sea-crossing passageways.