The defects in high-speed railway embankment will grow during operation. It will bring potential risk to railway safety. In order to develop an efficient detection method for the defects in embankment, a numerical simulation and field model test are carried out to study the influence of defect on wave propagation in embankment. A three-dimensional model of embankment and finite element method is employed, and the characteristics of wave form, amplitude response, and particle motion of sampling point on the slab are taken into account. The field entity model is a full scale one. It was built with materials in accord with the real railway embankment, and the construction methods were all the same. An elastic wave is excited by impacting on the surface of the entity model slab using a rubber hammer. The wave field is observed by vertical geophones on the slab. Common offset gather and common source gather are recorded for seismic imaging and elastic wave analysis. The result of the simulation agrees well qualitatively with that of the field test. It shows that the seismic imaging technique is effective for detecting embankment defects immediately under the slab.
