Abstract: In this paper, relying on the immersed tube tunnel project on the south extension of Fenjiang Road, the scale model of single-hole sand pressure is built, and the sand pressure process with varying sand-water ratiois adopted, and the relevant experimental research is carried out considering the infl uence of the anti-fl oating coefficient during the sand pressure process. The test results can provide references and references for the design and construction of sand foundations for immersed tube tunnels and similar projects on the southern extension of Fenjiang road.