NON-DESTRUCTIVE TESTING AND EVALUATION OF TIMBER AND STEEL H-PILES

Abstract

Timber and steel H-piles have been used in the construction of many aging locks, dams, levees, and other structures in the United States. Failure of these piles may adversely affect the structural integrity, and potentially cause damage and/or catastrophic structural failure. This study aims at utilizing state-of-the-art nondestructive testing (NDT) techniques to assess the condition of steel and timber piles. Two pairs of timber piles and steel H-piles were prepared and nondestructively tested in the laboratory. The test parameters were the two types of piles and pre-planned defect sizes/locations. Four NDT methods were investigated including bending wave (BW), dispersive wave (DW), combinations of dispersive-bending wave (DW/BW), and parallel seismic (PS). Wavelet transform, an advanced signal processing method, was used to post-process the NDT data. The method known as “peak identification (PI)” was used to detect the pile tip in both BW and DW/BW tests. The results reveal that the DW/BW accurately detected the pre-planned defects for timber piles. For steel piles, the PI method could only detect deeper defects in the DW/BW tests. The reflected signals from shallower defects had a relatively high signal-to-noise ratio and were hard to interpret. The wavelet transform approach was successfully used to detect both the shallow and deep defects in all the piles. The PS tests were proved to accurately and effectively capture all the pre-planned defects in both the timber and steel H-piles.