Most existing arch dams have been designed for seismic loading by static
methods involving the use of seismic coefficients. Although there are no
known examples of arch dams which have been seriously damaged by
earthquakes, the need for more realistic seismic analyses is now well
recognized, not only for new dams but especially in the context of the
safety evaluation of existing dams. Fortunately, with the finite element
method, engineers have a powerful tool for modeling the complex geometry
and the nonlinear material behavior of a dam. However, there is still a
major complication in the analysis procedure, namely the interaction of
the dam with the reservoir and with the foundation during an earthquake.
Interaction is a wave propagation problem involving transmitting
boundaries. The State of the Art in engineering practice is to neglect
wave propagation by modeling the water as incompressible and the
foundation as massless. More advanced analysis methods using
compressible water and foundation with mass have been available for some
time. However, these methods are restricted to linear models, because
they work in the frequency domain. On the other hand, there are also
advanced nonlinear models for dams, but they can only be used in the
time domain, usually with simple transmitting boundaries. In this
report, which is based on an a doctoral thesis, rigorous transmitting
boundaries in the time domain are developed which permit combining
compressible water with n- linear dam behavior. The new numerical model
is based on a systems-theory approach.