PSI - Issue 32

S. Yu. Devyatkov et al. / Procedia Structural Integrity 32 (2021) 56–63 S. Yu. Devyatkov / Structural Integrity Procedia 00 (2019) 000 – 000

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using a specific version of the computational iterative process: at each iteration, the finite elements adjacent to the roof boundary of the worked-out space of the tensile stress concentration sections were excluded from consideration (i.e. reset to zero) (Baryakh and Fedoseev 2011).

Fig. 1. A typical geological section.

The presence of clay layers in the roof of the longwall face is an additional factor that contributes to the destruction of the rocks. In this case, when the zone of the shear jointing reaches an open clay contact, caving of the rock into the worked-out space occurs (Baryakh et al. 2011). This caving criterion was also implemented in our calculations by localising and then excluding regions limited by an open clay interlayer and zones of shear jointing from the computations. Rocks caved from the roof of the longwall face fill the worked-out space, and form a technogeneousgeoenvironment due to decompaction; this was also included in the design of our mathematical model. The deformation properties were assumed to be an order of magnitude smaller than the corresponding indicators of the rock mass.It should be noted that the deformation properties of the caved rocks will change over time (Kocharyan 2016).