Abstract: Steel shell tubes are difficult to fill with unvibrated concrete, and the top surfaces often develop voids between the shell and concrete. Thus, the mix proportion is optimized for selfcompacting concrete that meets construction requirements, and selfcompacting concrete with good workability and volume stability is prepared. The casting method and chamber design are further optimized, enabling high quality and efficient segment prefabrication. In addition, model tests are conducted, and the testing results show the following. (1) Selfcompacting concrete prepared by injecting cementing material with a high content of fly ash and low content of slag can meet performance requirements, and the concrete is uniform and full after casting. (2) By controlling the casting speed and drop height of the concrete and increasing the number of chamber vents, no large voids occur between the concrete and steel shell.

Key words:  ShenzhenZhongshan link, steel shell immersed tube, mix proportion design, selfcompacting concrete, casting technology