TY - JOUR N2 - With reference to the situation experienced in several Polish collieries where the risk of occurrence of gas-geodynamic phenomena is increasing and decisions to start the mining activities need to take numerous constraints associated with previous mining into account, this paper addresses certain geo-mechanical aspects of longwall mining in the zones of excavation edge interactions giving rise to major changes in the conditions of the deposit and rock strata, as a consequence of previous mining operations in adjacent coalbeds. Starting from the analytical description of displacements and stresses in the proximity of longwall mining systems, the paper summarizes the results of model tests and investiga-tions of the influence that the excavation edge has on the behavior and structural continuity of a portion of the coal body in the coalbed beneath or above an old excavation. Based on selected nonlinear functions emulating the presence of edges in the rock strata, a comparative study is carried out by investigating two opposite directions of workface advance, from the gob area towards the coal body and from the coal body towards the gobs. The discussion of the results relies on the analysis of roof deformation and the concentration factor of the vertical stress component at the workface front. L1 - http://journals.pan.pl/Content/109828/PDF-MASTER/chlebowski-i-inni.pdf L2 - http://journals.pan.pl/Content/109828 PY - 2017 IS - Nr 99 EP - 170 KW - geomechanics KW - underground mining KW - confined conditions KW - rockbursts A1 - Chlebowski, Dariusz A1 - Burtan, Zbigniew A1 - Cieślik, Jerzy A1 - Zorychta, Andrzej PB - Instytut Gospodarki Surowcami Mineralnymi Polskiej Akademii Nauk CY - More info at Journal site: https://min-pan.krakow.pl/wydawnictwo/czasopisma/zeszyty-naukowe-instytutu-surowcami-mineralnymi-i-energia-pan/ https://min-pan.krakow.pl/wydawnictwo/wp-content/uploads/sites/4/2018/02/Wskazowki-ZN-ang-2018.pdf DA - 2017 T1 - State of stress and strain at the workface front under the old excavation edge SP - 159 UR - http://journals.pan.pl/dlibra/publication/edition/109828 T2 - Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi Polskiej Akademii Nauk ER -