| Summary: | 碩士 === 國立成功大學 === 水利及海洋工程學系 === 85 === The fracture geometry plays an important role in
understanding the movem-hat groundwater is likely to travel .
Because of the complex nature of geolog-ical formation,for most
former researchers assumed that heterogeneities in oneregion
were uncorrelated each other . The more evidences show that the
naturalrock does not follow such assumption . The exhibition of
correlations in theirproperties is often present at all scales.
This existence of such correlationhas necessitated the
introduction of "fractal geometry".
First the "Voroni graph" method of building a two-dimensional
fracturene-work structure is employed,that include both matrixes
and joints.Second, a fr-actal microscale fracture network is
obtained when self-similarity is imposedon the successive
scales of fractute network.Then,the application of cubic lawhas
been performed to calculate the volume that flows through the
two dimensi-onal fracture network.
In former day,the fluid flow through rock joint was commonly
described bythe parallel plate model.But real joint surfaces are
rough and often the roug-ness obeys fractal statistics.We use
"random midpoint displacement method" and"spectral synthesis
method " to produce isotropic and anisotropic roughness .Thus,
volume flows in a single fracture with a realistic shape can
be solvednumerically. The results show that:(1)At small
separations,the result deviatefrom the cubic law while at large
separations,the result has only little effe-ct(2)Because of the
possible effect of anisotropic roughness on fracture,thereis
larger volume flows through the anisotropic fracture.
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