12. Bridge Foundation Depth Estimation Using Sonic Echo Test

Nondestructive Tests are capable of determining unknown characteristics of the bridge foundations especially the depth of the piles and drilled shafts. Sonic Echo—Impulse Response (SE/IR) is one of the methods used in determining the depth of wooden and concrete piles and drilled shafts. When the top of the pile is inaccessible, sonic waves in the pile would be generated by either horizontally striking the side of the pile or striking vertically on a block attached to the pile surface. In the present research, in order to have reasonable criteria to determine the depth of piles, the data acquired by the sensors should be interpreted properly. In addition, while a sensor is mounted somewhere far from the top of the pile, the sensor receives different echoes at different times and reflection of the waves from the top of the piles and superstructures makes the case more complicated. In order to develop a methodology for testing and Interpretation, tests were conducted and analyzed in the laboratory and on railway bridges in New Mexico.