PRZYBLIZONA ANALIZA SCISKANIA FILAROW SKALNYCH W STANIE POKRYTYCZNYM. left bracket Approximate Analysis of the Compression of Rock Pillars in Post-critical Range right bracket .

An approximate method is presented for analyzing the behavior of rock pillars interacting with surrounding deformable layers under the action of a convergence of external layers treated as rigid. For this purpose a linearized model of the behavior of the rock material is adopted which takes into account postcritical softening in regions of low isotropic pressure and plastic hardening in regions of high pressure. It turns out that, depending on the geometric and stiffness relations, the pillar during the postcritical phase can deform either quasi-statically or dynamically. The latter deformation mode, often equated with pillar rock burst, can occur after a changeover in the behavior under loading to a catastrophic phase.