Application of Surface Wave Method to Confirm Compaction of a Refurbished Embankment – Case Study

In 2002 two extreme floods damaged the embankments of the river Kamp in Lower Austria nearby Vienna, because some parts of the dams are more than 100 years old. In 2009 it was decided to refurbish these embankments with the Impulse Compaction Method. To control if this compaction is successful surface wave seismic and dynamic probing was performed before and after the compaction. Results from refraction seismology indicate an improvement of the dam body after the compaction, but are not very accurate. Seismic surface wave results, which have a higher resolution near the ground surface, show a velocity inversion zone in 3-4m depth. This zone corresponds with the native soil upon which the dam was constructed. Furthermore there are in average higher velocities after the compaction down to the depth of 4m and no velocity changes below. Nevertheless the 2D-results of the seismic surface waves analysis indicates that the improvement of the packing density is laterally changing und goes locally deeper than the 4m depth. This is corroborated by the dynamic probing. Generally, it was demonstrated that the seismic surface wave analysis is a valuable tool to confirm the success of compaction and its penetration depth.