| Summary: | 碩士 === 國立中央大學 === 土木工程研究所 === 83 === Fluid flow through rock joints is commonly described by the
parallel plate model. However deviations from this model are
expected because real joint surfaces are rough and contact each
other at discrete points. In order to consider the surface
roughness effect on fluid flowing through joints, pairs of
rough surfaces generated by fractal model of surface topography
are placed together at various mechanical apertures to form a
series of "joints" and a finite element computer program is
used to calculate the seepage through such joints. The fractal
technique produces rough surfaces with homogeneous and
isotropic roughness. However the seepage through such joints
with small mechanical aperture presents a strong anisotropic
behavior. Simulations show that the areas of contact surfaces
and the size of finite elememt mesh of a rock joint are not the
reasons causing the anisotropy of seepage. Rather, it is caused
by the apertures variation of joints. When a joint with small
mechanical aperture, the variation of aperture distribution is
very large, so is the variation of seepage along different floe
directions. As the mechanical aperture increases the effect of
aperture variation decreases and the flow behavior becomes
isotropic.
|
|---|
