A finite element study on earth covered structures subjected to impact loading

For a wide range of practical applications a sophisticated nonlinear calculation procedure for soi1-structure interaction under dynamic load does not reward the efforts, since only small strain amplitudes are involved, and an elastic model would give similar and thus sufficient results. In certain cases however, e.g. where earth covered shelters or structures are to be protected against impact or blast loading, at least the inclusion of the predominant physically nonlinear features may be necessary in order to assess the response history properly. The recent development of finite element techniques /9/ has produced several promising calculation approaches in this field (e.g. ∕1∕,∕5∕). Nevertheless, any physically nonlinear model is necessarily an approximation, more or less suited to the real problem, and in situ measurements in the field under consideration are extremely rare. Even the assessment of the applied load is rather cumbersome in many cases. The scope of this - purely numerical - study was restricted therefore to topics such as: simplifications of a given model (in order to reduce the considerable costs of nonlinear dynamic analysis) without deviating too far from the main features of the response, the sensibility of the numerical response to parametric variations of a nonlinear constitutive model for a given geometry and load constellation, the effect of conspicious inhomogeneities in the vicinity of the structure (rock, ground water table), the extend to which the response for a given soil model and load can be altered by structural modifications.