The theory about the unsaturated soil is imperfect

and the settlement calculating method for the unsaturated soil is not mature because of the complexity of the unsaturated soil

foundation settlement calculation value and the measured values tend to have large difference so foundation settlement has become one of the main control factors for high-speed railway subgrade of passenger train special line.For unsaturated soil settlement problem

we analysis the characteristics of unsaturated soil foundation settlement of high-speed railway and obtain the load-settlement-time curve through centrifuge model test.Research results show that the unsaturated soil foundation has faster settlement in subgrade filling period

which complete 75% of the total settlement during the construction and after 5-6months short-term placement can amount to about 90% of the total settlement.The post-construction settlement can satisfy control requirements. In this paper

the results can provide a test basis for the theory of unsaturated soil settlement calculation.