Cone penetration test (CPT)-based stratigraphic profiling using the wavelet transform modulus maxima method

In this paper, a stratigraphic profiling approach is proposed based on the soil behavior type index, I-c, obtained from the cone penetration test (CPT). The basic idea of this approach is simple: the layer boundaries can be identified as the points at which a change occurs in the I-c profile. It is shown that these change points can be easily identified using the wavelet transform modulus maxima (WTMM) method. This method is able to accurately pinpoint the locations of change points in the I-c profile and to produce graphs and plots that fit well with engineers' methods of visualization and intuition. Moreover, by virtue of the fast Fourier transform, the computation is very fast. Case studies show that the WTMM method is effective for the detection of change points in the I-c profile. It is also capable of detecting thin soil layers.