HR: 1330h
AN: H42F-1130    [PDF]
TI: Effect Of Interaction On Apertures Of Multisegmented Natural Veins
AU: * Sim, Y
EM: gt7610a@mail.gatech.edu
AF: Georgia institute of Technology, School of Civil and Environmental Engineering, Atlanta, GA 30332 United States
AU: Germanovich, L N
EM: leonid@ce.gatech.edu
AF: Georgia institute of Technology, School of Civil and Environmental Engineering, Atlanta, GA 30332 United States
AU: Vermilye, J M
EM: jvermilye@whittier.edu
AF: Whittier College, Department of Earth and Environmental Science, Whittier, CA 90608 United States
AB: Echelons of multisegmented fluid-driven natural fractures (such as dikes, veins, and sometimes joints) with consecutive overlapping are one of the most common types of structures in the Earth­_s crust. The mechanical behavior of these fractures is quite different from that of single fractures, because of the interaction between the segments. In this work we compute the apertures of a highly segmented calcite vein, with 71 segments, in siltstone (Culpeper Quarry, Virginia) described by Vermilye and Scholz [1995]. The effect of elastic interaction between the segments is considered at three different special scales and accurately evaluated by solving the corresponding system of singular integral equations. For comparison, the case of ignored interaction is also considered. Our results unambiguously suggest that the effect of interaction highly affects the vein apertures. By using two net pressures in the vein as fitting parameters, it is possible to obtain an excellent match of the computed and measured apertures (based on 3,000 data points). This indicates two episodes in the history of vein evolution. Based on the performed simulation, a concept of effective fracture (vein) has been suggested. This is a single fracture of the same overall size (length) as the real vein. It is also pressurized by two net pressures that are determined by fitting the field data. As a result, practically the same net pressures are obtained as by accounting for the full interaction between the vein segments. The concept of effective fracture allows the sufficiently accurate computation of the vein (fracture) apertures, but without considering the interaction between the multiple segments.
UR: http://www.ce.gatech.edu/~leonid/rockmechgroup/research.html
DE: 1719 Hydrology
DE: 3210 Modeling
DE: 5104 Fracture and flow
SC: Hydrology [H]
MN: 2003 Fall Meeting