DISSIPATIVE STRUCTURES AND FRAGMENTATION AT MACRO- AND MEGA-SCALE
LEVELS IN THE ROCKMASS END PART IN DEPTH
I suggest that new scientific fields such as physical mesomechanics and synergetics of the rockmass end part that arose simultaneously and independently from each other should be united under a common name of mechanodynamics (as opposed to thermodynamics). Both the scientific fields should contain subsections of quasiequilibrium and non-equilibrium mechanodynamics.
Coal seam edge self-destruction is a typical problem of synergetic (slide 1, 2). Arising of a slip area in the coal seam edge is interpreted as generation of dissipative structures. The fact that mining science does not consider methane emission as a function of technogenous crack self-organization lead to crisis of conventional knowledge about coal methane.
The alternative mechanism starts to lay the major role at big depth (slide 3, 4), i.e. below the gas erosion zone, where coal seam edge self-destruction may occur.
The "rock mass - opening (cavity)" is an open system that may be far from mechanical equilibrium at big depth.
The self-destruction proceeds from the surface to the rock mass depth and lasts till mechanical equilibrium is restored due to generation of a post-failure coal zone.
If this zone is reduced critically or eliminated (slide 5, 6), another self-destruction cycle starts and proceeds at sound rate till mechanical equilibrium is re-established. If the increase in mechanical energy flow density is caused by another event, it results in stepwise growth of the post-failure zone following a period of elastic resistance of the rock mass. Rock opening conditions cannot be simulated by laboratory experiments. Similarly, results of field experiments depend upon experimental methodology, e.g. technical means.
The author demonstrates that the end part of a rockmass is a fractal (slide 7, 8), i.e. a multi-level self-organizing system for technogenic self-propelling fractures in which the loss of shear stability occurs in a self-consistent manner at micro-, meso-, macro- and mega-scale levels. This leads to emergence of dissipative structures (geomaterial fragmentation) at the above-mentioned scale levels.