Justification of the method of determination of the border overburden ratio Serhii Joukov, Serhii Lutsenko, Yulian Hryhoriev, Maxim Martyniuk and Volodymyr Peregudov E3S Web Conf., 166 (2020) 02005 Published online: 22 April 2020 DOI: 10.1051/e3sconf/202016602005