Time influence of tunnel support on the factor of safety Ivana Nedevska, Zlatko Zafirovski, Slobodan Ognjenovic, Ivona Nedevska and Vasko Gacevski E3S Web Conf., 157 (2020) 06002 Published online: 20 March 2020 DOI: 10.1051/e3sconf/202015706002