Ever wondered what those funny lines represent?

This short technical note will answer some (or all) of your questions
Background

The waterfall presentation, as required by the latest ASTM standard D6760-16, originates from the very early beginning of the CSL testing when analog oscilloscopes were used as data loggers (Levy, 1970).

Figure 1 - An early waterfall presentation

In this presentation mode, the voltage of each period along a given pulse is mapped to one pixel, as seen by Figure 2

Figure 2 - Raw signal captured by a modern A/D (Analog to Digital code converter) and the corresponding waterfall pixel representation of the digital code

Nowadays, all done by software, the waterfall presentation mode can be seen as a voltage(signal)-to-color, code mapping. Different mapping schemes may be used - such as full color, B&W or grayscale. Mapping can emphasize or, on the other hand, hide flaws in the tested profile of the pile.
Read more ....

Categories

Seismic, Soil Dynamics In-Situ

Keywords

Deep Foundations