Tunnel Roof Support is a support measure that uses L, u, I steel and steel rails, tubes and other steel profiles, processed into the required shape, and reinforced with whole joists or rods assembled to strengthen the underground works. The initial tunnel support is used to prevent excessive deformation of weak surrounding rock tunnels. Especially when the surrounding rock conditions are poor, limited to the surrounding rock itself and the site construction conditions, often leading to radial system anchor effect is not obvious, and increase the cost of tunnel construction, prolonging the construction period, at this time in the initial support in the addition of steel arch, can quickly provide sufficient support resistance, to meet the main rigidity required for the initial support, rapid control of the enclosing rock to continue to relax and continue to expand the plastic zone; limit the excessive deformation of the enclosing rock to ensure the stability of Support Arch structure system. Ensure the stability of tunnel support structure system.
(1) The overall stiffness of Steel Arch Support is larger, which can provide larger early support stiffness; the section steel arch can carry load earlier than the grating steel frame.
(2) Steel Arch Support can be well combined with anchor, steel mesh, shotcrete, constitute joint support, enhance the effectiveness of support, and better stress conditions. Especially the best combination of lattice steel frame.
(3) Grid steel frame is made of steel on-site processing, technical difficulties and requirements are not high; good adaptability to changes in tunnel section.
(4) The installation of Steel Arch Support frame is convenient.
