Dynamic response of embedded structure

An analytical and experimental investigation of the phenomenon of dynamic soil-structure interaction of buried structures was conducted. A shock impulse environment simulated by low velocity impact (free-drop impact system) was developed to generate a well characterized dynamic loading on the free surface. Small-model cylindrical buried structures, constructed of plexiglas and concrete, were then tested under this shock impulse system.;Low velocity impact of a circular plate resting on sand provided the vehicle by which the dynamic loading on the free surface was characterized. An analysis based on linear elastodynamics was derived for transient waves on a thin plate resting on an elastic half-space (sand). The measured response of the radial strain at the bottom of the target plate and the vertical acceleration of the sand beneath the center of the plate were compared with the analysis. The results provide an understanding of the plate vibration, of the interaction between the plate and the sand, and of the propagation of the load into the sand.;The dynamic behavior of a typical elastic buried structure was studied by using plexiglas; whereas micro reinforced concrete was used to study the behavior of a buried reinforced concrete structure. Loading relief at the center of the roof of the buried structures was observed. Furthermore, the stiffer structure was observed to experience less soil arching. When a linear-elastic dynamic analysis by the finite element method was conducted, the numerical results were found to have good correlation with the experimental observation of the peak displacement on the buried roof. However, the behavior after the peak response can not be simulated using the current linear-elastic formulation.