TY JOUR TI PROSPECTS FOR THE PRESERVATION AND MODERN USE OF THE COMPLEX OF DEFENSIVE STRUCTURES «THE MANNERHEIM LINE» KW fortification KW defensive structures KW Mannerheim Line KW conservation prospects KW modern use JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Bagaev, G.D. PY 2025 IS 10 PB Belgorod State Technological University named after V.G. Shukhov