There has been success stories that granitic residual soil has been used to fill the embankment for expressways; however

the most stringent standard will be applied to high-speed railways subgrade cumulative deformation under the loads of moving trains of the track structure which locate on the substructure; that granitic residual soil can be used for high-speed railway subgrade has not been verified so far. Based on the granite residual soil and its improved soil mechanical properties and deformation characteristics

using PMS-500 cyclic load equipment experimental research on dynamic performance of granitic residual soil subgrade of Wuhan-Guangzhou high-speed railway in Qingyuan region of Guangdong Province were made to study the applicabifity of granitic residual soil for filling embankment and subgrade bed. The dynamic performance and deformation performance of improved granitic residual soil subgrade bed were analyzed under 5×106 cyclic loads with and without influence of the subgrade surface flooding

quality variation of the subgrade with and without influences of rainfall. It is indicated that all the dynamic indices and residual settlement of improved granitic residual soil subgrade meet the design requirements of high-speed railways; even though 6.7 m high improved granitic residual soil subgrade has been prolonged soaking saturated infiltration; its settlement is less than 7.0 mm so that the improved granitic residual soil could be used to fill the embankment and subgrade bed of high-speed railways.