Soil stiffness properties of bridge pier determined by dynamic tests

The idea of determining of structural properties via dynamic test is well known. The main problem is to carry out the demanding dynamic test with appropriate equipment and accuracy. There were performed a relatively wide dynamic experiments in frame of the program of monitoring of structural changes of Austrian highway bridges by repeated dynamic testing. On the base of recent dynamic test of Warth bridge, which is situated near the Vienna on the highway Vienna-Graz, more interesting result have been found. The aim was to find out the eigen frequencies and eigen modes of this bridge and besides these accurate dynamic experiments also to assess the soil stiffness properties of the pier foundation.