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Chongbin Zhao B. E. Hobbs A. Ord Shenglin Peng Liangming Liu H. B. Mühlhaus 《Mathematical Geology》2006,38(8):987-1010
Exact analytical solutions have been derived rigorously for the pore-fluid velocity, pore-fluid-flow focusing factor, stream
function and excess pore-fluid pressure around and within a buried inclined elliptic inclusion in pore-fluid-saturated porous
rocks. The geometric characteristics of the buried inclined elliptic inclusion are represented by the aspect ratio and dip
angle of the inclusion, while the hydrodynamic characteristic is represented by the permeability ratio of the elliptic inclusion
to its surrounding rock. Since an elliptic inclusion of any aspect ratio can be used to approximately represent geological
faults and cracks, the present analytical solutions can be used to investigate the pore-fluid-flow patterns around buried
faults and cracks within the crust of the Earth. Therefore, the present analytical solution not only provides a better understanding
of the physics behind the pore-fluid-flow focusing problem around and within buried faults and cracks, but also provides a
valuable benchmark solution for validating any numerical method in dealing with this kind of pore-fluid-flow focusing problem.
The pore-fluid-flow focusing factor of a buried elliptic inclusion is demonstrated to be dependent on the aspect ratio, the
permeability ratio and the dip angle. 相似文献
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流域地貌演化的不同阶段沟壑密度与切割深度关系研究 总被引:9,自引:3,他引:6
主要探讨了在流域地貌演化的不同阶段,沟壑密度与切割深度的复杂关系,建立了沟壑密度随切割深度变化的理论极值模型及相应阶段的函数,补充了各演化阶段地貌形态要素的定量、定性描述;反之,可用沟壑密度与切割深度的关系推断流域地貌的演化阶段。 相似文献
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Haruo Sato 《Pure and Applied Geophysics》1988,126(2-4):465-497
The study of coda waves has recently attracted increasing attention from seismologists. This is due to the fact that it is viewed as a new means by which the stress accumulation stage preceding a large earthquake can be measured, since the scattering paths nearly uniformly cover a fairly large region around the focus and observation stations, compared with the direct ray paths. To date, we have had many reports on the temporal variation of the relation between coda duration and amplitude magnitude, and that of the coda attenuationQ
c
–1
which is estimated from coda amplitude decay. Some of these have shown a precursor-like behavior; however, others seem to have shown a coseismic change. We have critically reviewed these reports, and discussed what these observational facts tell us about the change in the heterogeneous crust. We found significant temporal variations, not only in the mean but also in the scatter ofQ
c
–1
, associated with the mainshock occurrence. The formation of new cracks, the reopening and growing of existing cracks, the interaction of these cracks, and the pore water movement through these cracks might correspond to such variations. In addition, we may expect an inhomogeneous distribution of crack clusters in a fairly large region, compared with the aftershock region. The gradual appearance of such crack clusters seems to be the most plausible mechanism by which coda decay gradients are caused to largely scatter in the stress accumulation stage. 相似文献