Sayed, I am sorry as the question is not clear to me. I know some methods and approaches to study the dynamic behavior of soil but "improvement methods"is not really clear to me. Did you mean the advanced methods for studying soil behavior? Please specify?
So, you know I am looking for what sort of methods used to enhanced dynamic behaviour of soil in the past and what kind of methods engineers using now? For example in a review paper author must mention and indicate the traditions methods and new methods. differentiate between them and propose a new idea.