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In this study, discrete Green's solution modelling the stress
waves propagating along layered geotechnical systems was used
to abtain the surface deflection of the system subjected to
dynamic loads. The seismic refraction and reflection methods
were theoretically studied by comparing normalized Green's
solutions recorded at various locations from the source with
the analytic time-offset curves computed using the raypath
theorm. The results of this study showed proper reliability of
the seismic refraction and reflection methods. Modelling of the
rigidity of baserock may influence the observation of
refraction waves. The groundwater position can be detected
using both methods. However, partial saturation of the soils
above groundwater level will contaminate such observation
especially when the saturation is greater than 50%. The offsets
between the source-receiver are found to be least four times
the sampling depth for better observation of refraction method
while it is suggested as 2~6 sampling depth for the reflection
method. The refration method is also found to be interpretated
easily without the wave interference. Moreover, the results of
the reflection wave observation show larger wave amplitudes
under arbitary condition.
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