Author/Authors :
Gaviglio، نويسنده , , Patrick and Bigarre، نويسنده , , Pascal and Baroudi، نويسنده , , Hafid and Piguet، نويسنده , , Jack-Pierre and Monteau، نويسنده , , Raymond، نويسنده ,
Abstract :
Stress measurements were carried out in the Arc syncline using drifs in a lignite mine. Eleven sites were investigated using the flat jack and hydraulic fracturing (or stimulating) methods. Two stress states were found to coexist, one isotropic, the other highly anisotropic. The orientations of the principal stresses are not homogeneous and an orientation ranging from E-W to NE-SW predominates locally. This does not accord with the regional stress field. The vertical stresses are systematically underestimated.
