Geomechaniczne własności łupków łyszczykowych Pasma Kamienieckiego z rejonu Krobicy

Stanisław Frelkiewicz, Piotr Kijewski, Jan Lis

Abstract


Określono fizyczne i mechaniczne parametry łupków łyszczykowych Pasma Kamienieckiego w Górach Izerskich. Obszar ten ze względu na perspektywy złożowej mineralizacji kasyterytem jest obecnie obiektem intensywnych prac geologicznych. Oprócz podstawowych własności geomechanicznych podano sposób deformacji łupków oraz określono anizotropię wytrzymałościową, wpływ nawodnienia i wszechstronnego ciśnienia na wytrzymałość badanych skał.

GEOMECHANICAL PROPERTIES OF MICACEOUS SCHISTS OF THE KAMIENIECKIE RANGE FROM THE KROBICA AREA

Micaceous schists of the Kamienieckie Range are characterized by high variability in mineral composition, texture and strength parameters. Three major varieties of schists were differentiated in the vertical section of the borehole K-II/3. The first variety comprises micaceous schists displaying highly advanced weathering processes. These rocks are brittle, with marked slaty cleavage and low strength parameters (Table 1). The other variety comprises compact micaceous-feldspar-quartz schists with high strength parameters (Table 2) and very coherent. The third variety includes micaceous-chlorite schists characterized by the: presence of feldspars and quartz and with intermediate strength (Table 3).

Physical properties of these micaceous schists are generally similar and not much varying. The schists are also characterized by low porosity and weight water absorption. Nevertheless, strength reduction due to soaking is significant, ranging from 25 to 50%.

Mechanical properties (Figs. 1, 4) indicate elastic-plastic material properties of these schists. The studies also revealed that the all-sided pressure significantly influences their strength (Fig. 3). The rocks also appear capable to energy storage as well as they display a trend to its dispersion.

With reference to D.F. Coafes and R.C Parsons (1966) classification accepted here, these are rocks of medium strength, elastic-plastic behavior when loaded, and ductile character a fracturing. Micaceous schists are characterized by a very high strength anisotropy related to their texture. Textural features are also the basic factor determining the mode of their deformation in· the course of destruction (Tables I, II).

Full Text:

PDF