InTrans / Aug 14, 2018

Determining the length of timber piles in transportation structures

Knowledge of pile length is a vital component for calculating the scour resistance of bridges. A nondestructive evaluation technique based on longitudinal stress wave propagation has been developed to determine the length of timber piles. A total of 33 piles from different bridge sites were selected for equipment evaluation and verification testing of the pile length
technique. The piles were evaluated by the stress wave technique, then compared to construction records for verification of length. The stress wave technique has been
proven to reliably estimate pile lengths between 20 and 60
ft with an accuracy of + 15 percent. Additional field tests
have been conducted on several bridges in Tennessee and
Colorado. Based on these field tests and signal processing
refinements, length estimates are possible for greater than
90 percent of piles tested.