Overwater depth inspection on a submerged pile bent

In this paper, a foundation inspection strategy was developed to determine the condition on a fully-submerged pile bent foundation supporting an overwater vehicular bridge in Taiwan. The electrical resistivity tomography inspection displayed the overall conditions of the salt-content canal. Using the reciprocal principle-based ultra-seismic inspection could finely determine the foundation depth. The time lapse analysis and traditional frequency analysis provided varying degrees of reliability on the pile length estimate, positively re-confirmed with the design charts. The entire investigation demonstrates the conclusiveness in determining the foundation depths when two testing methods are corroborated with appropriate analysis modes. (paper)