Improved Parallel Seimic Technique for Foundation Assessment

Nondestructive and geophysical techniques play an increasing role in civil engineering. Among<br>many others the investigation of pile foundations with unknown length is a major field of application.<br>There are many techniques as pile integrity testing, mise a la masse and parallel seismic, each with<br>special advantages. The parallel seismic technique (hammer impact on a pile head, registration of elastic<br>waves in a nearby borehole) benefits from the fact that it does not need calibration. First results using an<br>improved interpretation methods suggest that an accuracy up to 1% could be achieved. In addition,<br>information of the surrounding soil is acquired. The work described was done in the frame of the joint European project RUFUS (Butcher,<br>2003).