performance of nondestructive sonic echo testing method on partially dismantled unknown wood bridge foundations; a case study

Sonic echo (se) testing method is a well-known, versatile method to gather information pertaining to unknown bridge foundations. many studies on the applicability and methodology improvement of se tests to evaluate individual piles and foundations supporting the superstructure have been reported previously. however, there is a rare opportunity for obtaining the performance of se tests without the bridge deck. in the current study, three piles of a dismantled unknown bridge foundation were tested. unusual vibrations on velocity signals were found which are independent of the location of the sensors. such signals do not contain identifiable echoes from the pile toe. therefore, they cannot be used to determine the depth of the piles. the results and observations of this study show that there is little future application for conducting se tests on bridges that are out of service