Determination Of Unknown Depth Of Bridge Foundations Using Two Nondestructive Seismic Methods

This paper presents the test results of a research study on two nondestructive test (NDT) methods used for<br>determining the unknown depths of bridge foundations. Of the over 580,000 highway bridges in the National Bridge<br>Inventory, 106,000 (over-the-water) bridges have unknown foundation characteristics because no design plans are<br>available. Consequently, it is difficult for the state transportation departments (DOTS) to assess their susceptibility<br>to scour. Nondestructive and non-invasive test methods are needed to evaluate unknown foundation depth and<br>geometries.<br>This study documents the results for two acoustic NDT methods of Ultraseismic (a proposed new test<br>method), and the Parallel Seismic test method which were found to have the broadest application to the investigated<br>concrete, timber, and steel bridge substructures.