Caisson Evaluation by Stress Wave Propagation Method

The theoretical aspects of wave propagation were verified in the laboratory by experiments on bars of aluminum and concrete which showed that it is possible to detect discontinuities and abrupt changes in the cross-sectional areas of long members. The theory is based on stress wave propagation in elastic solids and on the Rayleigh theory of surface waves. Field tests demonstrated that the method could be used for in-situ installations of caissons and piles, resulting in very little interference with normal construction operations. Basic data and records are presented for laboratory experiments on aluminum and concrete bars, and field tests on cast-in-place caissons and piles. The results indicate that the stress wave propagation method has the potential for providing a simple, rapid, inexpensive, and reliable method for detecting irregularities in caissons and piles.