Harichandran, R. S., and Wang, W. (1990). "Response of indeterminate
two-span beam to spatially varying seismic excitation." Earthquake
Engineering and Structural Dynamics, 19(2), 173-187.
Abstract
In order to examine the effect of the spatial variation of ground motion
on the response of an indeterminate structure, the stochastic responses
of a two-span beam to spatially varying support excitations are
analyzed. A space-time earthquake ground motion model that accounts for
both coherency decay and seismic wave propagation is used to specify the
support motions, and the results are compared with those for various
simplified excitations that are commonly used in practice. The response
is computed through a linear random vibration approach with the
structure being modeled by finite elements. The results of the study
indicate that, even for moderate lengths, the effect of the spatial
variation of ground motion can be significant. The assumptions of fully
coherent support motions (same excitations at all supports or delayed
excitations allowing only for wave propagation) may be over-conservative
for some beams and unconservative for others.