This e-book explains the theory behind engineering aspects such as 1) dynamic loadings, 2) mathematical concepts 3) moving loads, 4) bridge support mechanics, 5) Static systems under dynamic loading 6) aero-elasticity, 7) space problems and 8) absorb systems (equations governing the behavior of the bridge-absorber system). The e-book is a useful introductory textbook for civil engineers interested in the theory of bridge structures.