Tóm tắt:

To protectthe large cross-section underground constructions at large depths, some countries in the vvorld (such as Russia, Poland, Ukraine, etc.) have put into use V-shaped Steel (SVPU) replacing U-shaped Steel (SVP). Because, V-shaped Steel (SVPU) has many improvements in geometric cross-section characteristics, the mechanical properties and joints construction wich help to increase the load carrying capacity, bending, tvvisting and stability level. Nowadays, Quảng Ninh underground coal mines are going deeper, so that the applying the V-shaped Steel (SVPU) increases the stability and security level for underground constructions in mines.