The pile-plank embankment is a kind of new-type of ballastless truck in high-speed railway. Based on the theorem of Bockingham ?

the dimensional analysis method is applied

and the dynamic model similitude constant of pile-plank embankment is determined. Dynamic characteristics of pile-plank embankment before and after soaking in water are analyzed by the large scale model test under dynamic loading. The test results indicate that dynamic stress of the soil decreases with the increase of vertical depth

and it is less affected by loading frequency. After the roadbed side-ascent soaking in water

at the same loading frequency

dynamic stress is slightly increased compared to embankment before soaking in water. Pile structure expands the depth of the dynamic response of roadbed and improves the stress of the roadbed soil. Bearing stratum at pile-bottom is greatly affected by dynamic loading; and it is one of the key of the dynamic design.