TY JOUR TI STRESS-STRAIN STATE OF A FIBER-REINFORCED EXPLOSION-RESISTANT BULKHEAD IN A COAL MINE KW coal mine KW fire KW explosion KW blast-proof bulkhead KW variational method KW stress KW strength JO Problems of risk management in the technosphere AU Kiryan, A.P. AU Peftibai, G.I. AU Galukhin, N.A. PY 2025 IS 2025 PB Saint-Petersburg University of State Fire Service of Emercom of Russia