All of which have application to the geotechnical engineer and should be seen as another tool in your toolbox.
Please post in this forum if you have any questions about how geophysics can help with your specific problem, or help better approach a problem you often encounter. Post a problem and some information on the project and let the geophysics community see what we can do to provide you a solution that can help.
I read your posting with interest. Sometime ago I inquired about a geophysical method called electroseimics (or seismoelectrics) which utilises a coupling system - seismics and electromagnetic waves in porous media. There is a electrokinetic effect caused by the movement of water with the creation a streaming potential. There might be a no. of uses in field applications in underground excavation, ground water monitoring etc. There is not much literature I could find on this method. Perhaps you might know something.