1st International Conference on Soil and Rock Engineering, Colombo, Sri Lanka, 6 - 11 August 2007, pp.1-5
Low strain pile integrity testing which utilizes one dimensional wave propagation theory makes it possible to detect major discontinuities or defects (cavities, cracks, decrease and increase in cross-section) within a pile quickly and economically. As the test data reflect the change in impedance, possible imped11ance diversity due to soil conditions must be known beforehand. In this manner, impedance difference caused by the discontinuities in the pile is distinguished and acquired. Using TNOWAVE’s SITWAVE application, pile integrity testing is simulated and signal matching procedure is executed. In order to achieve reliable results using SITWAVE, sufficient soil investigation must be performed to determine the soil layers and soil parameters properly. In the signal matching process, the test signal data are matched with the reference signal data simulated by the software. As the result of whole signal matching process, decrement in cross-section occurs in the first 1-2 m of all piles. This is caused because concrete has low strength in the pile head which is a general problem seen in drilled piles. In this type of discontinuity, it is proposed that concrete should be recast in the pile head.