This lecture comes from my CEEN 545 class, but it's applicable here. It will introduce you to the concept of using dynamic geophysical methods in-situ to measure the elastic (i.e., low-strain) properties of the soil. If you like this content, go check out all of my lectures in my CEEN 545 Geotechnical Earthquake Engineering series!

Now my friends Dr. Brady Cox and Dr. Clint Wood won't be mad at me for neglecting these topics in my last lecture! Lol...