DOREL ZUGRAVESCU, GABRIELA POLONIC, VICTOR NEGOITA
(ABSTRACT)
Rocks generally exhibit brittle behaviour when deformed rapidly by tectonic
activity and this characteristic is accompanied by a marked decrease of rock
mechanical strength.
The fissures, cracks, joints, etc., resulted by rock deformation mechanisms
have a great effect on the rock electric resistivity, because a fracture
filled with electrolyte opposes much less electric resistence to a current
flowing
along its length.
The first part of this paper tries to present, in the case of electric investigations
recorded by Romanian DRR method (Determination of Rock Resistivity), the
fissure and fracture effects on the electric resistivity, for the following
three different
situations:
1. Fissure and fracture spatial distribution (simple vertical fissure, simple
horizontal fissure, double vertical fissure directed towards two azimuths,
double fissure on horizontal and vertical planes and a fissure system spatially
oriented in 3 orthogonal directions.
2. Volumetric dimensions of fissure-fracture system expressed by its fissured
porosity.
3. Electric resistivity magnitude variations of the fluid filling the pore
space.
The last part of this work proposes mathematical relations and graphical
solutions, in order to evaluate the water saturation existing within the
intergranular
and fissured pore spaces.
Cuvinte cheie: investigarea electrica a sondelor, metoda DRR, roce fisurat-fracturate,
scoarta terestra superficiala.