One-dimensional wave theory is assumed to interpret longitudinal waves impulse response or impact echo testing results in concrete piles. Transient flexural waves tests are alternatively introduced to evaluate piles where the tops are inaccessible for conventional longitudinal wave testing. The resulting interpretation for flexural waves based on one-dimensional wave theory is improper due to various velocities at low frequencies. In this research, treating a pile as a waveguide, three-dimensional wave theory provides the dispersion relation between phase flexural velocity and frequency. Using the resonance solutions and first-mode flexural wave curve is a simple and efficient method to find the resonant frequency and phase velocity by knowing pile dimension and flexural IR results. The phase velocities at resonant frequencies measured in several flexural wave tests have good matches with the first-mode wave theoretical predictions at frequencies below 3,000 Hz. The boundary conditions for practical feasibility are discussed for different in-situ conditions.
Wang, Helsin; Chang, Ta-Peng; and Wang, Jin-Jun
"RESPONSE ANALYSIS OF CONCRETE PILES SUBJECTED TO LATERAL IMPACT,"
Journal of Marine Science and Technology: Vol. 18
, Article 9.
Available at: https://jmstt.ntou.edu.tw/journal/vol18/iss6/9